Authenticity in the restoration of monuments Authentizität in

Authenticity in the restoration of monuments
Authentizität in der Denkmalpflege
Leuven, 2003
Authenticity in the restoration of monuments
Authentizität in der Denkmalpflege
Colloquium, 14 maart 2003
Editor: D. Van Gemert, K.U.Leuven
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Preface
International colloquium
Authenticity in the conservation of monuments
WTA organises this colloquium on “Authenticity in the Restoration of Monuments –
Authentizität in der denkmalpflege” in Leuven on March 14th 2003. The colloquium takes
place in the Promotion Room of the University Hall of K.U.Leuven at Naamsestraat 22,
Leuven. This building was constructed in 1317 as the guild hall of the weavers guild, by the
architects Jan Stevens, Arnold Hore and Godfried Raes(the present Gothic ground floor).
The newly founded university moved into the Krakenstraat wing in 1432. In 1679, the
University purchased the entire building from the City of Leuven and added the present
Baroque wing at that time. The Rega wing, with its classical sandstone façade facing the Old
Market, was built in 1723. The Hall and the University library, which was located there, were
destroyed by the German Army in 1914 in a reprisal. The university hall was restored in
1922 and now houses the Rectorship of the University.
Sscientists coming from different countries express their vision on the subject 'Authenticity in
monument conservation'.
Sessions are chaired by Jo Coenen, Nederlands
rijksbouwmeester, and Bob van Reeth, Vlaams bouwmeester. Contributions and opinions
are presented by Bert van Bommel (NL), Stefan Grell (G), Koen Van Balen (B), Luigia Binda
(I), Hubert Jan Henket (NL). The Charter of Venice (ICOMOS) stresses the importance of
preserving the original substance of a monument. But what if a bishop shuts the door of his
church and the building collapses, and when only two columns survive the destruction?
Should the two columns be left in place, or should they be removed, in view of a
reconstruction?
The Brandeburger Tor is known to have had a light colour in one period, but also a dark
colour in other periods. What should be considered as the authentical colour?
Keeping a historic mortar may be dangerous for a monument. Should it be substituted?
A 100 years old monumental school should match the needs of the present time. May one
alter certain characteristics of the building according to one's own vision? These are only a
couple of practical questions that are raised in the quest for authenticity at restoration of
monuments.
During the colloquium the speakers will discuss different theories and concepts, but also
practical problems that people responsible for the maintenance and conservation of
monuments need to face and resolve in a well-considered way. The speakers will share their
experience and thoughts with the participants in the colloquium, hoping that a fruitful
discussion will take place.
WTA has tried to provide an high standard syllabus of the different lectures. We hope that
these proceedings will serve as a start for further discussion, sharing of information and
continued interest and research.
Leuven, 12 maart 2003
Prof. Dr. Ir. D. Van Gemert
Vice-president WTA
President of WTA Nederland-Vlaanderen
Contents
Chairman morning session bOb van Reeth
Wim Denslagen
The Dual Meaning of Authenticity
Bert van Bommel
Search for a new interpretation of the concept of
authenticity.
A theory of relativity for the field of heritage-care
Stefan Grell
Das Brandenburger Tor –
restaurierungs-ästhtetischer Sicht
Jo Coenen
Vision on interventions in the urban monumental
space
betrachtet
aus
Chairman afternoon session: Jo Coenen
bOb van Reeth
Cultural durability
Koen Van Balen
From
Luigia Binda
Compatibility between safety and authenticity:
the experience of Noto Cathedral Noto – Sicily
Hubert Jan Henket
Conservation of Modern Architecture; paradoxos,
dilemmas and approach
conservation
principles
to
materialisation
THE DUAL MEANING OF AUTHENTICITY
Wim Denslagen, Rijksdienst voor de Monumentenzorg
1. Introduction to Authenticity
Authenticity has raised itself to a godlike stature in the world of conservation. The notion is
much older than Romanticism, but since then it has been essential in the world of conservation
in Europe, the homeland of Romanticism. Outside Europe authenticity is probably not known
in the specific sense in which it is used in the field of restoration. In Japan for instance it
means, according to Nobuo Ito, something like genuinity or reliability, which is somewhat
different from the European meaning [1].
Words have no meaning of their own. They are always and necessarily related to the context
in which they are used. In the world of conservation is has become a common practice to use
the word original if one wants to denote the thing as it was made originally, but the word
authentic denotes the thing as it came down to us through history. Take for example the
Dreikönigenhaus in the Simeonstrasse in Trier, which has been built, in the third decade of the
thirteenth century. Before its restoration in 1974, the house was still authentic, in the sense
that it showed its passage through the ages, but in 1974 the house was restored to its original
appearance, as it had been built in 1230. This original appearance is a reconstruction of 1974
and is as such something new, a new construct. The authentic, unrestored house has been
destroyed in the process.
This difference between originality and authenticity is essential in the world of conservation.
Something is called authentic to discern it from something, which has been changed by a
recent intervention. The only notion in this definition, which is liable to change, is the word
recent. A historical monument is called authentic in relation to its unauthentic state, which
presupposes a change, whether a reconstruction or the rebuilding in a different form.
Therefore one could say that the cathedral of Notre-Dame in Paris was authentic before 1850,
but inauthentic after the restoration by Eugène Viollet-le-Duc. But now, after 150 years, his
restoration is considered an authentic monument of the nineteenth century [2].
The way in which many architects took the liberty to change historical monuments met much
criticism during the nineteenth century and this paved the way for the modern charters on
conservation and restoration. According to these charters restorations should be limited as
much as possible to mere repair. The charter of Athens recommended in 1931 that
‘permanent maintenance’ was to be preferred above restorations and the Charter of Venice
stated in 1964 that conjectural restorations should be avoided [3].
These kinds of messages can be traced back to the age of Romanticism, the period, which
produced a new sense of the past. A well-known example of this message can be found in the
Promenades dans Rome (1828) by the French novelist Stendhal. In this retrospective on the
eternal city, Stendhal explained how outraged he had been at the sight of the restored Arch of
Titus. Of this antique triumphal arch, commemorating the capture of Jerusalem by emperor
Titus in Anno Domini 71, only the archway itself and some decorations on the front had been
preserved, since it was incorporated in a medieval wall. The reconstruction by architect
Giuseppe Valadier in 1811 met with the profound disapproval of Stendhal, who wrote: ‘Instead
of supporting the arch of Titus, which was on the verge of collapse, with iron props or with a
brick buttress, whereby confusion with the original work would have been precluded, this
lamentable figure has rebuilt the monument. He has been so bold as to cut new travertine after
the example of antique blocks, and to set the new pieces in the place of the old. The antique
work has been removed, where to I do not know. What remains is a copy of the Arch of Titus,
although one has to concede that the site is still the same and that the reliefs on the inside of
the arch have been preserved’ [4]. Stendhal demanded respect for the fabric of the historic
monument, for the authentic substance.
This is the first meaning of authenticity.
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2. The second meaning of authenticity
Stendhal and many others romantics rejected insincerity in the arts, not only in the case of
restorations, but also in the production of art. That is why Stendhal disliked the academic art of
his time, because he wanted art to be real. He despised art which was based on classical
models and which looked like copies of famous masterpieces. After he had visited the Salon of
1824, the famous exhibition in the Louvre in Paris, Stendhal wrote that he was ‘enjoyed’ by the
many paintings, which were nothing else than clever copies of the approved and accepted
works of the classicist Academy [5]. Sincerity became the hallmark of true art during
Romanticism.
The famous novelist Emile Zola expressed in 1866 the same feelings as Stendhal did in 1824,
when he, Zola, in his turn commented on the Salon and wrote that for him ‘a work of art should
be a personality, an individual’. He hated paintings, which ‘were produced by pupils who follow
the work of their masters’ [6].
This second meaning of authenticity, sincerity and honesty of the artist, who rejects imitation
and tries to express his true feelings, has had an immense influence on modernism. To be
honest in art meant the rejection of all that is superficial and unnecessary. The modernists
wanted to forget the artistic mimicry of the nineteenth century and wanted to return to the basic
essential. That is why the modernist Ludwig Mies van der Rohe showed his audience in 1923
pictures of primitive dwellings, like tents and huts. He wanted them to forget all about the
worthless trash of the nineteenth century art (ästhetischen Schutthaufen) in Europe and to
look with fresh eyes at an Indian tent and an Eskimo hut [7].
The first meaning of authenticity is related to the care of old art and denoted the untouched
work of art, the historical substance. The second meaning refers to the honesty of the artist in
his work. The difference between the two meanings is sometimes mixed up. A recent example
can be found in an article of the Belgian architectural historian Geert Bekaert. He was worried,
he said, about the new wave of architectural imitations and the compliant response of those
who are responsible in this field. Heritage is no make-believe, Bekaert wrote, and should be
part of our living world. According to him heritage can only be of importance if it will be
incorporated in our current culture ‘in an authentic, creative and critical way’. In this sentence
authentic means something like sincere (the second meaning), but in the context of his article
there is a relationship to the first meaning. The relationship is expressed by his rejection of
imitations [8].
Both Geert Bekaert and Stendhal hold the view that imitations are always inauthentic, in art
and in restorations. This view has had an enormous influence in the world of conservation
through the writings of John Ruskin.
But the problem with this view is that it has produced a certain anomaly, which is also to be
recognised in the Charter of Venice (1964). In this document the making of imitations is
condemned and one suspects that the condemnation is based on the romantic idea that a
copy is unauthentic. According to article 12 ‘missing parts’ should be ‘distinguishable’ from the
authentic work in order to avoid historical lies. The result of this recommendation has been
that architects are incited to create new forms for the missing parts. The old form of for
instance the tracery in a window, which fell apart some years ago, is not to return, although
there might be enough evidence to produce a copy of the lost tracery. This fear of not being
‘authentic’ has encouraged the disappearance of many old architectural features, which are
doomed to be wiped out of the collective memory. The charter rules out the possibility to even
transfer the forms of historical architecture to the next generations. The missing parts are
replaced by new design, which have in most cases no formal connections with the historical
design. Old architecture should die in beauty according to John Ruskin and his followers in
Venice.
The confusion of the two meanings of authenticity seems to paralyse the traditional restoration
practice and the question is if this attitude is reasonable in regard of the speed old architecture
vanishes in our modern world.
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3. More authenticities
During the Nara Conference on Authenticity, which has been organised by the ICOMOS in
Japan in 1994, the German architectural historian Michael Petzet proposed to develop various
forms of authenticity. He could discern authenticity of form, of material, technique, function and
site. A year earlier a comparable proposal was published by the Dutch art historian Nicole Ex
in her book Zo goed als oud (1993). She discerned four authenticities: the concept of the artist,
the function of the work of art, the original appearance of the work and the historical
development of the artwork. She proposed that there should be made a choice out of these
different authenticities, when it comes to the restoration of the work of art. These proposals
have had some influence in the world of conservation, as can be shown by the educational
publication of A.J. van Bommel Instandhouding (2001).
It is difficult to understand why it would be of any help to give different meanings to
authenticity. These proposals seem to destroy the foundations on which restoration principles
are based, because if the first meaning of authenticity, the substance itself, will not be
accepted anymore as a fact, you are free to choose the definition of authenticity you like best.
The thing itself, the material authenticity, might have the same value as the original concept of
the artist. This means that you would be allowed to change the work of art to the original
concept. If the authenticity of the substance itself loses its defined position, the consequence
could be that the restorer is given the possibility to return to the attitude of for instance Violletle-Duc, for whom the concept of the artist was far more important than the appearance of the
work of art in its historical development.
It seems not necessary and only confusing to introduce more than one meaning for the word
authenticity in conservation. It would have been better to use the word value for the other
notions. The original concept of the artist is a value, like the original or later functions of the
work of art. These are values and not authenticities.
It was very confusing that various participants of the Nara Conference used the word
authenticity to describe a historical value. One of the Japanese participants, Hiroyuki Suzuki,
said that in Japan ‘in case of traditional wooden houses, people change roof thatch every ten
years and repair the bases of the wooden pillars of their house every generation or two. This
cyclical and repetitive maintenance maintains the essential living heritage.’ According to
Hiroyuki Suzuki this tradition is a value in itself and should as such be protected. Cultural
traditions should be valued as authentic, as much authentic as the material object in western
traditions.
The Nara Conference explored the possibilities to broaden the concept of heritage, in the
sense that it should be possible to protect also local cultural traditions. ‘Authenticity’, Marc
Laenen stated in Nara, ‘lies not only in the physical structures of the built heritage, but
essentially in the continuation of the evolution and development of society.’ He meant that
heritage is changing very fast in our modern world and that cultural diversity is going to
disappear, unless we are willing to protect these local cultural traditions. The discussions in
Nara were not aimed at the destruction of the notion of authenticity, but they were aimed at the
protection of immaterial things, like traditions in local cultures, for instance in building
traditions, in farming and landscape. It is perhaps a mistake to conclude that authenticity has
lost its first meaning, that the authentic substance is an illusion.
4. References
1. Nobuo Ito, ‘ Authenticity Inherent in Cultural Heritage in Asia and Japan’, Proceedings of
the Nara Conference on Authenticity in relation to the World Heritage Convention (Nara,
Japan, 1994). ICOMOS 1995, 35-45.
2. Wim Denslagen, Architectural restoration in Western Europe: controversy and continuity.
Amsterdam, Architectura & Natura, 1994, 95
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3. La Conservation des Monuments d’Art et d’Histoire. Rome, Office International des
Musées, 1933 and Nessun Futuro senza Passato. Rome, ICOMOS, 1981.
4. Derek Linstrum, ‘Coup d’oeil rétrospectif. Giuseppe Valadier et l’Arc de Titus’,
Monumentum (1982), 43-71
5. Stendhal, Mélanges d’Art. Paris, Divan, 1932, 44-47 and David Wakefield, Stendhal and
the Arts. Phaidon 1973, 101 en 102
6. Emile Zola, Salons. Paris, Librairie Minard, 1959, 61
7. Ludwig Mies van der Rohe, ‘Gelöste Aufgaben’, Die Bauwelt (1923), 719
8. Geert Bekaert, ‘Kan het erfgoed de architectuur redden?’, Erfgoedzorg in de 21ste eeuw.
Kritische Beschouwingen. Gent, Koning Boudewijnstichting, 2000.
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IN SEARCH OF A NEW INTERPRETATION FOR THE CONCEPT OF AUTHENTICITY
A RELATIVITY THEORY FOR THE HERITAGE CONSERVATION SECTOR
Bert van Bommel, Atelier Rijksbouwmeester
1. Introduction
One of the most important documents for our profession is the World Heritage Convention
[1], which describes heritage as a multifaceted concept. The term heritage is used to refer
both to the natural heritage and to the cultural heritage [2]. This is (probably unintentionally)
more revolutionary than might at first appear. Experience has shown us that within the
sphere of cultural heritage there are areas and domains that, while they share the same
basic notions, nevertheless approach ethical aspects quite differently. In the preservation of
historic buildings, for example, the emphases are different in each specific sector. An
architect working on a restoration project sets different priorities to the restorer of an organ
or a windmill. In the case of the organ, the quality of the sound is crucial, while in the case of
the windmill it is important to preserve its function as a utility object. If we then turn our
attention to the preservation of other historic artefacts, then even greater differences come to
the fore. To say nothing of the conservation of the natural heritage, which has developed an
entire nomenclature of its own.
Nevertheless, when discussing the thinking about the ethical principles underlying heritage
conservation, I would like to encompass the whole of the heritage conservation sector, as
referred to in the World Heritage Convention. And when I speak of authenticity, I would like
to define it in such a way that it can be used both for the natural heritage and for (all forms
of) cultural heritage. Not just because we are sometimes called on to weigh one against the
other, for example when we find there are rare and precious ferns growing on a historic
building that urgently needs repointing. More important even than this is the fact that this
universal approach could lead us to richer and more mature insights, because we can
deepen those insights using all aspects of heritage conservation.
In terms of the ethics of heritage conservation, there are quite a number of interesting
problems to draw attention to. The problem that I will be addressing here (what is
authenticity?) is in my opinion by no means the most thorny. The most difficult is the
problem of the legitimacy of the internationally accepted codes of conduct. However, the
question of what authenticity is, is part of that issue – as it no doubt is for every question
relating to heritage conservation. For that reason, I would like to begin by outlining the
problem of legitimacy, so that it can be considered during our further discussion about
authenticity. Otherwise we run the risk of later being in complete agreement about
authenticity without realising that the golden statue we have fashioned between us has feet
of clay.
An entirely different problem is that of what I should like to call the problem of priority (and
of posteriority). I will be returning to this at the end of this article. In doing so, I will try to
establish a link between heritage conservation and other interests (such as architecture and
town planning).
1.1. The problem of legitimacy
The question at the heart of the ethics of heritage conservation is – in my opinion – the
question of the legitimacy of the prevailing charters, treaties and conventions.
The heritage does not belong to us, but to those who engendered it and to those who will
come after us [3]. We simply have it in trust, on loan. Nor does it belong to the individual or
individuals who happen to be its legal owners; rather it belongs to the community as a whole
[4]. And the heritage of each community is the heritage of the global community [5]. This
leads me to the conclusion that a conservator or restorer is not given his brief by the
individual he happens to have concluded an agreement with. His principal is the global
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community, and not just that of the present, but that of all time. But to what extent do those
who have drawn up our charters, treaties and conventions represent that global community
of all time? To what extent is their opinion legitimate [6]?
To some extent, I can provide an answer to the legitimacy question as I have presented it.
That answer distinguishes two fields. The first is that of the professional world. Professionals
are uniquely involved in heritage conservation and are therefore able to deepen their
understanding of it. They are better able to do so the more – and the more intensively – they
exchange views with other professionals. It is probably redundant to do so here, but I would
nevertheless like to put forward a plea for dispute and debate. It is crucial in the interests of
legitimacy that professionals are constantly and intensively engaged in an exchange of
views about the ethical problems they encounter. Within the Dutch heritage conservation
world, I have noticed that following decades of relative radio silence, a spirit of debate
appears slowly but surely to be emerging once more. This is most welcome, and I would like
to take this opportunity to encourage it.
The other field is that of the man in the street. As a heritage conservationist, I abhor attempts
to restore historic buildings as if they were completely new or to their former glory. Yet the
average man in the street values the most appallingly over-restored objects. And let us not
forget that the average man in the street constitutes the vast majority of the global
community. He is the principal I must keep before my eyes [7].
My answer to the problem this creates for me is that this fact must not lead to deceitfulness.
The value of the insights of professionals is too great to be traded in for a democratically
determined morality. Yet clearly, the gulf between the professionals and the average man in
the street must be closed. Not by having us as professionals conforming to the layman’s
preferences, but by constantly and consistently making ourselves accountable. We must not
restrict ourselves to merely deliberating amongst ourselves. We must share our insights with
the rest of society, we must work on communication and information, we must be open to
questions – and even provoke them – and we must never be too indolent to provide answers
and to consider and discuss what laymen put before us [8].
So let’s return now to the problem I am to examine here: what is authenticity? Naturally I am
prepared to say a few words about this. But not unconditionally. I expect opposition – debate
even! – and I expect the insights acquired to be shared, not just with professionals, but also
and above all with the man in the street. Only then can my contribution be regarded as
useful.
In my view, a key condition that must be applied to this debate is the universal approach to
heritage conservation. If we want to redefine the term authenticity – and I shall be
demonstrating that we do indeed need to – then this term must be universally applicable.
Universal in the sense that it is applicable throughout the entire sphere of heritage
conservation, whether it involves vintage cars, documents, the visual arts, architecture,
landscapes, archaeological or palaeological remains, or the environment, flora or fauna. This
applies equally to another term that I shall be using and that I have borrowed from the
museum world: ‘musealisation’.
1.2. Heritage conservation as a three-pronged approach
What we now regard as our heritage was originally an ordinary part of everyday life: a
utensil, a building, a plant, an animal. An object only becomes part of our heritage when it is
recognised and acknowledged as such. It is then no longer ordinary, but has – at least for
whoever has recognised and acknowledged it – been invested with a new significance.
This leads to the need for study. Study concerning value. What makes heritage into
heritage? In our profession, we generally refer to this as culture value study, but in parallel to
this, we can also, when we are talking about the natural heritage, refer of course to nature
conservation value. For my present purposes, in the interests of the universal approach, I
will refer to it as the value study (or investigation of evidence). This involves something
rather unusual, since this study will after all lead to a revised recognition and
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acknowledgement of the heritage. This process is therefore characterised by a cyclical
nature.
Finally, this process leads to the need to preserve the heritage, to oppose those processes
that undermine (the value of) the heritage. In theory, it makes no difference whether this
takes the form of a nature-lover who opposes poachers or encroaching urbanisation, an
archaeologist who is trying to prevent a disastrous drop in water table levels or an architect
who is repairing the roof of a building and unblocking the guttering. This part of the process
can also be part of a cyclical movement. After all, a preservation measure can bring to light
new facts that can lead to a revised recognition and acknowledgement of the heritage.
Figure 1: The three-pronged approach to heritage conservation: recognition (musealisation),
value study (towards proof of authenticity; the investigation of evidence) and
action (intervention)
Incidentally – though this is a marginal aspect – although ethical questions aren’t only a
factor playing a role in the final stage of this three-pronged approach, they do occur primarily
at this stage. Recognition and acknowledgement, as well as value study, are fairly innocent
pastimes [9]. Conservation measures always require a weighing up of various aspects. A
weighing up of interests, in the form of both a single heritage-based interest against another
single heritage-based interest (internal heritage-based considerations) and the weighing of
several heritage-based interests against other interests (heritage-based interests versus
external interests). This weighing up of interests is briefly discussed in § 5, in the problem of
priority and posteriority.
2. Musealisation
Musealisation is a well-known term in the museum world. It describes the desire of societies
to preserve objects and to place them in museums. This inevitably changes these objects,
either physically because they are restored, or in terms of their connotation or emotional
value. Utensils, for example, are placed in an entirely different context and thereby change
from utility objects to museum objects. They thus become special!
The term musealisation can however also be used in a narrower sense, namely to denote
what happens to an object when it is included in a (museum) collection, or to indicate how
the relationship between a person and an object changes when that object becomes part of
a collection.
The term musealisation, as used in the museum world, can’t simply be applied to buildings,
urban and village-scapes, landscapes and threatened plants and animals. Musealisation is
after all chiefly about removing objects from their original function and (physical) context.
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The built heritage can’t be collected in the same way (i.e. placed in a different context) as
can paintings, old clocks or sugar packets. But the term musealisation is also useful when
we’re considering preserving heritage that isn’t gathered together in a museum (or zoos or
botanical gardens). The term only requires a minor, subtle change in definition to be able to
be used heritage-wide.
Musealisation is the recognition (acknowledgement) of heritage. Musealisation goes
hand in hand with a change in our relationship with the heritage (concerned).
Using this definition, musealisation can be applied to all forms of heritage (recognition of the
tiger as a threatened species, recognition of a building as an unusual example of the work of
a particular architect, recognition of a painting as the work of a recognised master).
The application of this definition not only makes the term universal in the sense that it can be
applied to forms of heritage. It also becomes universal in the sense that it need not simply be
applied broadly (the desire to collect, the ascribing of a category) or narrowly (inclusion in a
collection, the recognition of a single object or artefact). In this way, it relates more to the
actual underlying process and can therefore also relate to parts (elements) or aspects of an
object (of heritage-care).
Meaning
musealisation
of Examples
Example of consequences
Recognition of the value of old Old clothing is collected and
costumes
included in the museum
collection
Musealisation
in
a Recognition of the post-Second Start
of
stock-taking,
broad sense
World War period as a significant selection and preservation
period of architectural history
Recognition of labourers’ songs Registering text and music on
as a valuable part of the cultural paper and on recording
and historical heritage
equipment
Recognition of a coat in a jumble Purchase and inclusion in a
sale as part of a regional collection
costume
Musealisation in the Recognition of a building as an Conservation as a protected
narrow sense
interesting example of the work monument
of a particular architect
Recognition of a song as a pile- Making a recording of the
drivers’ song
song
Recognition that a certain The
coat
becomes
decoration or trimming is unusual particularly special due to the
application of that specific
decoration
Musealisation of an Recognition of a particular The
monument
acquires
element or aspect
feature in a piece of the built added significance due to the
heritage
particular feature
The pile-drivers’ song turns out The song is included in a
to contain some long forgotten study of the historic use of
words from the nomenclature of language on construction
pile-drivers
sites
The musealisation of an aspect or part of an object or artefact can invest that object or
artefact with (added) significance. It can even cause a non-musealised artefact to be placed
in a museum. Hence a painting that is unremarkable in itself may be musealised due to the
fact that it has an unusual frame, or an unprepossessing building could be musealised due
to an unusual feature, or a meadow could be musealised because it is home to a rare plant.
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We see that all these recognitions are indissolubly linked to a change in our perception of
the heritage to which they relate. This recognition alters the heritage, even if only in the
sense that it is our relationship with it that changes. In practice, however, it appears that
there is also often a genuine change in the heritage, since this altered relationship also alters
the way in which we approach the heritage. And so we erect a fence around the nature
conservation area where the rare ferns are growing, we ban the trade in ivory, we hang the
painting in a museum, place the clock in a case and remove the non-authentic safety belts
from the vintage car. Crucial in all this, however, is the change in our relationship with the
category or the object, once this category, this object or this aspect of an object is
recognised as heritage [10].
2.1. A closer look at musealisation
When we musealise something, when we designate it as part of our heritage, our perception
of it changes. This is partly determined by the viewpoint from which we musealise it. The
effect of musealising a building as part of the output of a particular architect (hence from the
viewpoint of architectural history) differs significantly from the effect of musealising the same
building as a fascinating example of visible history. In the latter case, changes that the
building has undergone over the course of centuries will be particularly important and
valuable, whereas in the former case, these changes would be perceived mainly as
disruptions to its original design. The same applies when a landscape is musealised. If this is
done from the perspective of it being a centuries-old polder landscape, then the effect will be
wholly different than if it is recognised as an environment in which specific plants and
animals occur. The angle from which we musealise things is thus crucial for the way in which
an ordinary object that evolves into a piece of heritage is accompanied by a change in our
perception of what is being musealised. Obviously this will also define the angle from which
we investigate its value.
Figure 2: A polder landscape. A nature conservation area or a cultural landscape?
Based on the premise that the heritage must be approached on an integrated basis, we must
see this as a danger. After all, if we musealise a polder as a cultural landscape we could
easily lose sight of its natural value (and vice versa, if we musealise it as a nature
conservation area, then there is a risk that we might underestimate its cultural value). The
recognition of a building as an important part of the work of a particular architect could cause
us to dismiss the value of later additions, but conversely, its musealisation on the basis of its
being a fascinating example of visible history could lead us to undervalue it original design.
The premise that heritage must be approached in an integrated way therefore leads to the
conclusion that the value study should also be conducted in an integrated way, from all
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possible angles. Given our tendency to approach things from a single viewpoint, we must
make a conscious effort to look for other possible perspectives in order to come to a
balanced judgement. This may appear obvious, but we must acknowledge that in practice,
the logical multidisciplinary approach on which the value study is based, is not so evident.
On the contrary, value studies are generally carried out from a single perspective or from a
number of closely related perspectives.
Musealisation not only relates to concrete, physical aspects such as objects, buildings,
instruments, machinery, sites and landscapes. It can also relate to objects that have no
(actual) physical substance: customs, practices, traditions, songs and crafts. Not only is it
possible to musealise a rare plant, but we can also musealise the incidence of that plant in a
particular landscape, the (rediscovered) existence of a threatened animal, or the (continued)
ability to make something according to a certain traditional methods. For a long time, this
played almost no role in western thinking about the physical, material heritage. When, at the
request of the World Heritage Committee, a group of experts were asked to consider the
question of what precisely authenticity involved, the result was not a tidy new definition of the
term. The final document [11] did however provide new, valuable points of address with
which the term ‘authenticity’ could be approached. This consitituted a justified (eastern)
response to the eurocentric, primarily material-based tone of documents such as the Venice
Charter [12]. In subsequent conventions and treaties, however, these new insights did not
make a prominent reappearance. This is a pity. Here in the west we naturally don’t need to
conform to these eastern insights, since by doing so we would be ignoring our own cultural
inheritance. On the other hand, we are missing an opportunity if we do not reap the benefits
that we can gain through these eastern insights. We should therefore include these aspects
in our considerations, even though the priorities we weigh against each other will remain
western ones. We may then, for example, accept that preservation through the use of
traditional materials and techniques will probably do more to undermine the authenticity of
the fabric of the artefact than modern conservation techniques based on scientific insights.
But we will also appreciate that the regular use of traditional materials and techniques
preserve other forms of heritage in the form of traditional crafts and skills. So when we
intervene in heritage we must always weigh up different interests [13], given that we will
always be forced to relinquish some aspects of authenticity in order to uphold others. But it
would be a tragedy if in doing so we were always to neglect the intangible value of heritage.
So we must, in our own western way, include this in our considerations. However, the
prerequisite must be that this intangible value must also be included in the value study.
2.2. The principle of ongoing musealisation
In an article I wrote in 2001, I expounded the principle of ongoing choice [14]. This principle
states that we are faced at every moment with the decision of whether or not to intervene, to
take action in the face of processes of encroachment and deterioration. An intervention will
always be at the expense of part of the value of the object, yet every decision not to
intervene will similarly result in a loss of value due to ongoing processes of deterioration.
The principle of ongoing choice makes one aware of this and can be used as a tool to
determine the nature and precise moment of (a well-considered) intervention.
Seen in that light, the choice that we often make these days in favour of passive
conservation is highly understandable. It is after all not about a short-term end result (such
as the end product of a project), but about a process. The important thing is the long-term
result, the preservation of the heritage for posterity, to which a shorter-term goal is
subordinated.
Musealisation also involves an ongoing process. Here, too, the systematisation of
musealisation is of great importance in the formation of our thoughts. One consequence of
this is that the study on value can never attain a definitive result, but must always be a
continuous process. This is in fact highly logical, since we experience all of it. A description
of a monument, the sale of a painting, the insights gained concerning the importance of a
sculpture: all are effectively already out of date by the time they are published. Initially it
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appears as though this is due to external factors, such as scientific progress, which renders
accounts outdated. But this is not the only factor at work.
When someone recognises – musealises – a heritage object, then they will initially do so
only superficially. The recognition itself elicits further study, an initial value study. When the
insights gained are shared with others, this also results in their musealisation by others
(obviously assuming that these others agree about its heritage value). That creates new
perspectives (those of the others).
Apart from the value study, interventions can also lead to renewed musealisation. After all,
when an object is subjected to an intervention, new facts may be discovered and those facts
can lead to a revised musealisation. Each heritage-based object is therefore constantly
musealised, and as a result is constantly changing in significance.
Figure 3: Musealisation is a process determined both by internal factors (knowledge of the
object) and by external factors (knowledge of the – a lot of – contexts)
The consequence of musealisation is the changing of the heritage object, often also in a
physical sense because the musealisation prompts interventions that may lead to a physical
alteration [15]. This also results in the need for a revised musealisation.
Finally we must conclude that the value that we ascribe to the heritage is also determined by
our cultural outlook. In a different cultural perspective, we might well ascribe an object no
value at all or else regard a different value as more important. Since culture is not a constant
but is endlessly changing, the attribution of value is therefore also time-bound. Certainly in a
western society, which is characterised by a relatively rapidly evolving culture, this means
that a value attribution only has a very limited shelf life.
The result of this ongoing musealisation is especially significant where the choice involves
interventions. The way in which we approach the heritage-based object is defined by the
stage at which the musealisation process finds itself at that particular moment. If we were to
opt for a particular intervention either earlier or later, then we would have chosen a different
method of intervention!
Meanwhile, however, the heritage object will also change, will move away, as it were, from
the state it was in when we initially encountered it. Not for nothing did John Ruskin sigh,
when he saw what was being done to (acknowledged) historic buildings: Restoration, so
called, is the worst manner of destruction [16].
3. The inevitable shift of context
There are also objects that are actually made and intended for life in a museum. This
applies, for example, when artists are asked by museums to organise a ‘happening’ or are
commissioned to create a work of art for a specially designed museum space. This is
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nothing new. Long before the first happenings were taking place in museums, many talented
artists were turning their hand to the decoration of rooms in museum. The only difference
was that in the museum’s eyes this was often not a form of art. Later these works were
frequently covered with whitewash so that ‘genuine’ art could be enjoyed without hindrance.
The decorations disappeared, together with the many plaster casts of classical sculptures,
which are now (because they are not ‘real’) banished to basements or carted away as
rubbish. Not that everything that hangs in museums is all that genuine. We need think only
of the complete skeletons of prehistoric animals on display in our natural history museums,
which are sometimes little more than reconstructions based on a handful of rediscovered
bones [17].
Most of what is on view in our museums has been removed from its original context (and
that applies equally to zoos and botanical gardens). The Archers Guild of Captain Frans
Banning Cocq and Lieutenant Gerard van Ruitenburg (1642), the famous painting by
Rembrandt Harmensz. Van Rijn (1606-69), was clearly intended to be admired. But it was
meant to be admired as the jewel in the crown of the Amsterdam bowmens’ squadron, for
whose committee room in Amsterdam’s archery guild the painting was actually intended,
rather than to be displayed on loan at the Rijksmuseum to be enjoyed by millions. For these
millions, no visit to the Dutch capital is complete without a trip to see this Nightwatch. To say
nothing of the heavy glass box protecting the portrait of the Mona Lisa or La Gioconda
(1503-05) by Leonardo da Vinci (1452-1519), which hangs in the Louvre in Paris: this
painting was never intended to be seen under these conditions. Altarpieces originally
designed for incense-filled churches, instruments from laboratories, furniture from salons,
statues from gardens, seals for envelopes, stones from facades, cars from roads, tigers from
jungles – there’s nothing you can think of that we haven’t wrested from its original
environment, put in a collection and displayed in the foreign context of an exhibition hall.
However, it is by no means true that an alteration of context need be solely physical. It can
also have other consequences. Keith S. Thomson refers in his book Treasures on Earth to
the effect that museums, by collecting objects, have in removing them from the market been
partly to blame for the huge price increases that they themselves are adversely affected by.
However, it is not just museums that do this, since there are few postage stamp museums in
the world, and despite this, a stamp originally worth half a cent can now command
astronomical values. This in itself doesn’t say a great deal, since (if I may again quote
Thomson) one could almost make it a rule that any artefact labelled a ‘collector’s item’ is not
worth collecting [18]. Collector’s items have simply been ascribed the context of
‘economically valuable’ even if they are nothing more than knick-knacks or simple utilitarian
objects. The public at large is highly impressed by the sometimes fabulous prices demanded
for collector’s items and devours television programmes like Tussen Kunst and Kitsch
[Between Art and Kitsch], the Dutch version of the BBC’s Antiques Roadshow. Recently [19]
the programme opened with the amazing words …an extremely badly preserved
reproduction of a Toorop. Even if it had been in good condition, its value would still have
been zero, but in its present condition it’s worth half of that…. As if this wraps up the work’s
entire cultural and historical value!
Apart from the fact that the context changes in the sense that an object’s commercial value
increases, there are also other changes in context that may be regarded as more
substantial. I’ll take a building as an example so that we can move away from museums now
and concentrate more on historic buildings. But you could just as easily use the examples of
museum artefacts, threatened plant and animal species or anything else that can be
musealised.
When I left primary school and went on to secondary education, it was then that I entered
the Technical College in Vlaardingen for the first time. This building was completed in 1955
and I first set foot in it 11 years after that. For me at the time it was just a school building
where I admittedly enjoyed going but which didn’t mean much more to me than that. After I’d
left the college I initially returned to it a few more times, but very soon the building was no
more than a vague memory. However, when at the end of 1996 I was preparing an article on
heritage (and potential heritage) objects in Vlaardingen [20] I revisited the building to see
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whether I should devote any attention to it in my article. I immediately noticed its careful
design, and the balanced way in which the various elements of the building had been
grouped and placed in counterpoint. I suspected that it had been designed by a highly
talented architect, and on closer study I found that it was by Dirk Roosenburg [21], which
explained a great deal.
Figure 4
My recognition of this post-war monument changed the building in my perception from an
ordinary edifice, a vague recollection of my school-days, into a monument that I felt needed
to be preserved. Apart from calling for attention to be given to it on National Heritage Day in
1997, the theme of which just happened to be school buildings [22], I also brought it to the
attention of the authorities via the Vlaardingen Historic Buildings Committee. The building’s
next door neighbour, the Unilever Research Laboratory [23] (the town’s biggest employer),
had since submitted an expansion plan involving the demolition of the technical college. The
Vlaardingen Historical Association asked the Amsterdam-based architectural historian
K. Zita Messchaert to study the building [24] and the Historic Buildings Committee similarly
asked Peter Nijfhoff of the Government Heritage Agency to give an opinion on its
architectural merits. Now that Unilever’s expansion plans have provisionally been shelved,
the immediate danger of demolition has abated. Moreover, local politicians and officials have
now been made aware of the fact that the building is of significant cultural and historic
importance [25].
Figure 5
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During this process, the building was frequently musealised. First of all by me, then by
supporters of the Vlaardingen Historical Association and the Historic Buildings Committee,
by the researchers who had been called in, and, finally, by the public given information and
by civil servants and administrators. The way in which all these people looked at the building
had now radically changed. The relationship between object and subject had been altered.
But above all, the building acquired many new contexts. It was not relocated, nor were there
any changes to its environment, so in a physical sense its context remained unchanged. But
it has now been given a place among the town’s key post-war buildings (in terms of
architectural history). The building has also obtained a context in the form of the work of Dirk
Roosenburg, in the development of architecture during that particular construction period,
especially that of school buildings, buildings for secondary education and – more specifically
– of technical colleges. It has even gained a context in the potential urban redevelopment of
the district. In that particular context, it is seen by the government officials most closely
involved chiefly as a problem case, and not as an opportunity. I assume there is no need for
me to put forward my own opinion where this last aspect is concerned.
Figure 6
Figures 4, 5 and 6. Vlaardingen, Technical College on the Veerweg (Deltaweg), 1955.
Architect: Dirk Roosenburg in partnership with Verhave and Luyt.
4. Authenticity
An extremely badly preserved reproduction of a Toorop … Clearly, that such an object is
valueless must be obvious even to the smallest child. After all, not only is it in a poor state of
preservation, it isn’t even a genuine Toorop, merely a reproduction. It isn’t real, it’s not
authentic.
The word authentic has now been so frequently misused, and has had its meaning changed
so often, that we can justifiably ask ourselves whether we can still use it.
Whereas when it was first used it still denoted originality, that which was handed down to us
unchanged, now we realise that it cannot be used in that sense. After all, what is original? If
we look at an old building, then the difficulty is obvious. Originally, there was a principal who
wanted an edifice built and an architect who gave form to that requirement. An imaginary
form admittedly, since it was a form that existed only in his head. As soon as he began to
turn this form into practical reality, by committing it to a drawing or sketch, he was confronted
straightaway with the recalcitrance of reality. The forms in his head, which consisted of
rooms, specific atmospheres, relationships and decorative schemes loaded with meaning –
all these had to be modelled into feasible, realisable forms which satisfied the Euclidian laws
of proportion and conformed to the laws of nature, such as gravity.
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Once they were in the hands of a builder, the architect’s drawings then had to be interpreted
and turned into a building in which, apart from the drawing, the mores of the guild and the
hand of the carpenter and the bricklayer all had to be given their due. And once the building
had been completed, the ravages of time, wars and accidents, and the whims and ideas of
successive owners and users would also leave their traces. Identifying a single moment in
this endless procession of events as the single moment at which the building was in its
original form is not just perilous and arbitrary but also has little use other than as a purely
intellectual exercise. Moreover, designating a particular state the building was in at a
particular moment in the past as its original state has no practical value. The building is after
all no longer in that state and no matter how carefully we study everything, we will never
(fully) recapture its actual state at that shadowy moment. That state is imaginary [26]!
It is not so much this post-modern, relativising perception that has led to the term authentic
being revised. On the one hand, it has in any case been debased by being increasingly
linked to a commercial value. On the other hand, it has become unusable through having
been constantly misused. It is of little consequence now whether it refers to the architect who
wanted to recreate a monument in a form that the building once might have had or whether it
refers to the form that was intended by the original architect, but was never realised [27], or
indeed whether it refers to the architect who recognises the value of all the changes that the
building has undergone down the centuries, and who wishes to preserve these changes or
even wants to add his own features. This last interpretation has led to the introduction of the
clumsy term advanced historical authenticity [28].
The seven different forms of authenticity [29] that we can distinguish through all this tinkering
with the original term do not however satisfy me. (I’ll leave it at seven for the moment, since
this ties in with the discussions I have been hearing in the Netherlands; if I thought about it
for a bit longer I could certainly come up with more.) These forms don’t satisfy me, not
because each form involves a denial of other aspects of authenticity. It is not that they are
not usable tools; quite the contrary. They don’t satisfy me because they contain the risk of
such a form being seen as the only authenticity, rather than – as is actually the case –
simply being a facet, a mere part of that authenticity.
But what, then is the authenticity, that universally applicable, all-encompassing certificate of
genuineness? It is when the musealised has attained its maximum value. After all, value is
what it is all about [30]! However, this assertion faces us with the problem that during the life
span of the musealised object, value is constantly being ascribed to it and also taken from it.
Is the authenticity then necessarily an imaginary and practically inapplicable term?
4.1. Value
The authenticity, that is, what we want to preserve through our heritage conservation, lies
not in the fabric – hence in a building, not in the stones, the mortar, the wood or the paint.
The purpose of our efforts is therefore not to preserve those things! Rather its purpose is to
preserve the reason why the building is significant, namely its cultural value. It is about
maintaining the artistic work and the historical document, about maintaining the value. And
the most important means of preserving that value is the conservation of the physical fabric
[31].
Let us begin, then, by looking at the value. In contrast to what some would argue or suggest,
value is not an intrinsic quality. A token example is the value of money. If you have half a
million euros in your pocket and you’re in the middle of a desert, you will probably attach
more value to a bottle of water than to the cash. The value of that money rests solely on a
mutual agreement between people, and despite this, there are situations in which that value
is not important and in which something that in other circumstances is of little value can
appear to be far more important. Value is not an inherent property; it can be ascribed!
The moment at which we ascribe value is, it can be argued, the moment of musealisation.
This is a crucial moment, since it is the moment at which the heritage changes from
something ordinary and everyday into heritage. We know that the consequence of that
musealisation is, that recognised heritage will change, and – we can also be sure of this –
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that it will lose some of its value because every change involves a loss of value. Since the
earlier situations in which the object found itself are imaginary, there is no point in defining
any one of them as authentic. However, if we decide to link the authenticity to the status quo
at the moment of musealisation, then we have established the term authenticity at the
moment when that heritage still has all its value, thereby causing us to recognise it as
heritage [32].
Authenticity is the value that can be ascribed at the moment of musealisation.
This notion incidentally means that authenticity is no longer absolute, but that it has become
a relative term. It is relative within the complex of values (that can be) ascribed, and relative
in the sense that authenticity depends on the viewer and on the moment of viewing.
At the moment of musealisation, some of an object’s value is clear and visible, while some of
it is still hidden because it is only through (closer) value study that it will (or could) emerge. A
status quo assumes a calculation of the authenticity of all that value, known or unknown.
Value can relate both to what is materially present (i.e. what is generally regarded –
incorrectly as it happens – as the intrinsic value) and to value that has no (direct) link with it,
as set down in the closing document to the Nara conference: purpose and significance,
meaning and so on.
An analysis of an object’s value produces many different types of value. These are moreover
impossible to compare and have different weightings. So it is not just the different values we
must consider, but also the weighting ascribed to those different values. The (seven)
different forms (facets) of authenticity recognition are an attempt to impose a structure within
that value and to ascribe a weighting to value. Such models are therefore useful when it
comes to having to make decisions. Even so, they remain artificially limited constructs and
we must never lose sight of the risks they entail!
In that sense, it is dangerous to give an example of this complex of values, since they can
never be exhaustive. Nevertheless, I believe that examples can be produced. When I look at
a small historic building in my immediate neighbourhood [33], then the first value I would like
to ascribe to it is its significance as a historic and architectonic element in one of the oldest
and still fairly well preserved districts of the town. The building itself is a model historical
record. I recognise in it a seventeenth century dwelling, which therefore must have been built
shortly after the fire that destroyed most of the town. But I also see how in later centuries the
façade has been altered. Not only has it been made higher, but the entire ground floor
frontage has been replaced and its function has been changed from a dwelling to a
warehouse.
Figure 7: Vlaardingen, Smalle Havenstraat 23. Warehouse (former XVII century dwelling)
Inside it I see a roof construction and layers of beams, which testify to the same history. I
can now also examine the window frames more closely and see that these appear to date
partly from the original construction period. Others belong to the later building phases.
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Looking more carefully at the materials I can see that a variety of different types of brick
have been used, as well as different mortars and forms of pointing. I can even see two
drying hooks. These are rare. In some Dutch fisher-villages, hooks like these were and still
are found in seventeenth century fishermen’s dwellings. A pole was laid across the hooks so
that oilskins could be hung out to dry.
The façade has (fortunately) never been cleaned, so the grey patina of this little building has
an appropriately ancient dignity. As a seventeenth century dwelling, the building is important
due to the link it has with the fire that destroyed the town, which presumably rendered the
whole of the then town uninhabitable, with the possible exception of the suburbs. It is
therefore a luctor et emergo [triumph over adversity] façade, and, partly in view of the few
buildings that remain from that time, it is of great importance for the town.
I could go on in this vein, but as you can already see, I have already cited a series of
different aspects that are often impossible to compare with one another. Value in the urban
context and value as a representative of history, value as a fascinating example of changes
during its history and value as a demonstration of the materials and techniques used in the
past. Mortar and pointing as well as the being-there in the context of the historic town.
4.2. The viewer as a yardstick for authenticity
A good friend of mine owns the cockerel wind-vane from the spire of the now demolished
Nieuwe Kerk [New Church] in the town where I live [34]. He is proud of this artefact, which
he saved from a skip. But I always wince when I see it because it reminds me of the lovely
church that is no longer there. In fact I couldn’t remain in the same house with it.
The cockerel is obviously an important historical document; I recognise that. But my
emotions get in the way whenever I look at it. What I see in the first instance is not that
historical document, that gilded metal form beaten by centuries of wind and rain, but the lost
church to which it is the almost the only surviving testament. What I see above all is the ugly
monstrosity that has now come to stand on the site of the former church and in my
imagination I wander forlornly over the foundations of the building that is no longer there
[35].
Clearly, the viewer constitutes an important factor in musealisation and hence also in
interpreting the term authenticity, as I have defined it [36]. My authenticity is not the same as
that of another person, who looks at the object through different eyes. There is a parallel
here with the term monument, as defined in Dutch law. A monument is an object that is of
universal importance due to its beauty, its significance for study or its cultural and historic
value. The term is subjective, since what is regarded as being of universal importance
depends on the viewer. For you, that value will be different from that of your neighbour or
from that which I ascribe to an object. In law, therefore, a distinction is made between a
monument and a protected monument. A protected monument is included in a register and
from this it derives the necessary objectivity (legal clarity).
We must also ascribe a similar objective variant to the term authenticity, in addition to the
subjective authenticity that I have put forward above, in order to remove the notion of
subjectivity from the discussion. Something, in other words, that we could call objective
authenticity. This objective authenticity [37] is then the complex of values that can be
ascribed to an object at the moment of musealisation, with as its subject the global
community. This then covers all the value that is (or could be) attributed at the moment of
musealisation. This makes objective authenticity elusive, and a term that can only be
approached through a detailed study of an object’s value using all conceivable relevant
disciplines. But does that mean it has also become an unworkable term? I don’t think so.
Applying the term authenticity in this sense is in fact useful. If we want to use it to base a
decision on, then we are obliged to conduct a detailed interdisciplinary study and we are also
obliged to constantly remember that we can only ever know part of the value. The rest is (as
yet) hidden from us, but our interventions must ensure that we preserve as much of it as
possible. We are thus obliged to strive towards reversibility, towards a minimum level of
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intervention, and towards compatibility and other tools that will help us, despite the
incompleteness of our knowledge, to intervene as responsibly as possible.
This, together with everything else that I have put forward, will enable us to complete the
definition of the term authenticity:
Subjective authenticity is the weighted sum of all the value attributed by a single
subject at the moment of musealisation.
Objective authenticity is the weighted sum of all the value attributed (and potentially
attributed) at a single moment of musealisation.
It is the objective authenticity of the heritage that we must do our utmost to preserve. We
must take decisions to intervene in heritage whenever this objective authenticity is at risk.
And when we intervene, we will be forced to sacrifice certain aspects of that objective
authenticity in order to uphold other aspects. We will then be faced with an (internal heritagebased) weighing up of interests (value). Often, and especially in the case of historic
buildings, external interests will also play a role in our decisions. We will then need to weigh
the desire to preserve authenticity against disparate elements such as safety, commercial
efficiency, modern comfort and – very prosaic but real nonetheless – the size of our
available budget. No matter how important it is that we agree on authenticity, how we
approach it and how we deal with this conflict of interests is even more important.
And of course, these definitions oblige us to constantly indicate which particular moment of
musealisation the authenticity we are talking about relates to. The authenticity of today is
different to that of the past. The authenticity of an object can have been reduced, but – if, for
example, a substantial artistic value has been ascribed to it – it can in fact also have
increased!
5. The problem of priority and posteriority
In the Netherlands, historic buildings have recently been plagued by civil servants who insist
that they meet statutory fire regulations. I agree with them to some extent, which is to say
that I agree that these buildings must be made fire-safe. What I don’t agree with is that they
should literally meet all the statutory requirements, even if this erodes their historic value.
After all, there are many ways in which fire safety can be achieved [38].
Recently I was asked to provide material for the compilation of a quality yardstick. What
criteria should a building meet in order to be judged as being of high or low quality?
The centuries-long struggle between architects and historic building conservators lies in the
degree to which architects are allowed to realise their designs and concepts at the cost of
the monument.
These are three problems that all relate to the question of the priority and posteriority of
interests. The importance of monument-value, the importance of safety, the importance of
architecture, and so on. These are interests that we must weigh against each other. But in
order to weigh up interests you have to give them a certain weighting. Sometimes the
importance of safety weighs more heavily than a building’s historic significance, and
sometimes it is the other way around. Sometimes an architect has an idea or a design in his
head that is more important than (the part or aspect of) the monument that has to be
sacrificed to it, and sometimes this is not the case. You will understand that it is a
complicated weighing up process, and this won’t be the last time you hear me refer of it.
After all, each situation is unique and requires its own considerations [39]. Yet despite this,
there is something general we can say about it.
First of all, there are interests that are significant only to individuals, and there are other
interests that are important to a larger group. Now it may well be that the interests of that
one individual weigh so heavily that they take precedence over the minor interests of a large
group. But it can also be said that the interests of a large group will generally take
precedence over those of an individual.
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Figure 8: The interests of a large group weigh more heavily than the interests of an
individual
Figure 9: The four groups distinguished during the categorisation of interests
Heritage conservation scores well in this regard, since the heritage is after all of importance
for the world community of all times. The users of a public space, local residents, passers-by
and tourists all occupy a second leading role in this. They are generally more numerous than
the third group I distinguish here: namely those who have to work on the construction and
maintenance of a building and those who live or work in the building. The group that I
allocate the lowest priority in this scheme is the group that is socially usually the strongest:
the owners and employers [40].
In this scheme, a major heritage interest such as environmental conservation or the
preservation of cultural heritage, weighs more heavily than a major architectural or urban
development interest. Yet at the same time, we must not lose sight of the fact that a major
interest of an owner can weigh more heavily than a minor heritage-based interest. So the
consideration remains a difficult one, and I can’t pretend it doesn’t. Nor should we
underestimate our creativity. In cases where, for example, we cannot implement a fire safety
measure due to the immense historical value that would be compromised by it, we can often
instead use our creativity to put in place other measures that are either comparable or at
least ensure that the building meets an acceptable level of safety. Where a historic building
is standing in the way of an urban planner, this constraint can spur him to use his creativity
to come up with an even better solution. And where the architect appears to be hindered by
a historic building in which he cannot give free rein to his ideas, he may well find that in
-15-
agreeing to submit to the limitations it imposes he comes up with even better, more inspired
solutions. It is the quality of the fire prevention officer, the urban planner and the architect
that decides whether a good solution can be found in spite of the conflict of interests.
Practice has shown that historic buildings can be seriously threatened when that quality is
below par; alternatively, they can be really come into their own if they are handled by the
right people.
Figure 10: The various interests classified in terms of their overall priority and posteriority
It is doubtless through these same spectacles that you should filter any lecture by an
architect. What is their attitude to historic buildings? Do they come to them with the aim of
upholding the craft of the architect, are they committed to using their creativity in the service
of preserving their heritage value? If that is the case, then I am completely in agreement with
them.
6. References
1.
2.
3.
4.
World Heritage Convention, ratified in Paris on 16 November 1972.
The World Heritage Convention covers the built heritage, but there is no reason in
principle why we should restrict ourselves to that in this article.
JOHN RUSKIN: The Seven Lamps of Architecture. Sunnyside Orpington [George Allen],
1880 [ed. princ. 1849], p. 197: Of more wanton or ignorant ravage it is vain to speak; my
words will not reach those who commit them, and yet, be it heard or not, I must not
leave the truth unstated, that it is again no question of expediency or feeling whether we
shall preserve the buildings of past times or not. We have no right whatever to touch
them. They are not ours. They belong partly to those who built them, and partly to all the
generations of mankind who are to follow us. The dead have still their right in them: that
which they laboured for, the praise of achievement or the expression of religious feeling,
or whatsoever else it might be which in those buildings they intended to be permanent,
we have no right to obliterate. What we have ourselves built, we are at liberty to throw
down; but what other men gave their strength and wealth and life to accomplish, their
right over does not pass away with their death: still less is the right to the use of what
they have left vested in us only. It belongs to all their successors. It may hereafter be a
subject of sorrow, or a cause of injury, to millions, that we have consulted our present
convenience by casting down such buildings as we choose to dispense with. That
sorrow, that loss, we have no right to inflict. […]
The Athens Charter for the Restoration of Historic Monuments 1931: II. Administrative
and legislative measures regarding historical monuments.
-16-
5.
6.
7.
8.
9.
The Conference heard the statement of legislative measures devised to protect
monuments of artistic, historic or scientific interest and belonging to the different
countries.
It unanimously approved the general tendency which, in this connection, recognises a
certain right of the community in regard to private ownership.
It noted that the differences existing between these legislative measures were due to the
difficulty of reconciling public law with the rights of individuals.
Consequently, while approving the general tendency of these measures, the
Conference is of the opinion that they should be in keeping with local circumstances and
with the trend of public opinion, so that the least possible opposition may be
encountered, due allowance being made for the sacrifices which the owners of a
property may be called upon to make in the general interest.
It is important to underline a fundamental principle of UNESCO, to the effect that the
cultural heritage of each is the cultural heritage of all. The Nara Document on
Authenticity, 1994.
One underlying principle of the ethics of heritage conservation is the (broadly accepted)
understanding that heritage ‘belongs to everyone’. This is effectively a political
statement. What is remarkable is that this principle is also accepted by those whose
political convictions do not accord with this. It is a marginal observation, but important
enough to mention. The notion that heritage belongs to everyone fits in with a socialist,
or even in fact a communist ideology, and not with the global neo-liberalism that
currently predominates in the western world (compare the ideological statement that
knowledge belongs to everyone with the assertion that knowledge is a capital good).
This statement shows us that the ethics of heritage conservation are in fact (partly)
based on political ideology and perception. So in contrast to the thinking of many
historical monument conservators, monument conservation is therefore not politically
neutral. This will also be revealed at the close of this argument, in which a political
observation can be read between the lines.
Keith S. Thomson carefully queries the legitimacy of the principle that heritage belongs
to everyone: Parallel to the individual collector’s passion there exists a common public
drive, often expressed as a public ‘right’, to ‘own’ works of art and other cultural objects.
It derives in part from a deeply rooted feeling that the public has, in every legalistic as
well as philosophical sense, an ‘interest’ in the materials of culture. … As culture is no
longer the sole province of the wealthy few, the private ownership of great works seems,
in this post-Marxian world, less and less politically and philosophically appropriate.
KEITH S. THOMSON. Treasures on Earth. Museums, Collections and Paradoxes, London
[Faber and Faber], 2002, p. 49-50.
Although, I think the only way to encounter this problem is to accept that the global
community of all time is a Form (eidos), perceived by reason or the intellect, not the
senses, in the way Plato made a difference between knowledge and true believe, based
on experience and experiment.
In many problems relating to heritage conservation, it is also important to involve
economists, social administrators, experts in jurisprudence and politicologists. The
arguments presented here show that in a multidisciplinary approach to heritage
problems of this kind, journalism (news management) should also have its place.
Musealisation and the study of an object’s value are obviously also not entirely free of
ethical considerations. Not long ago in Roermond, there was a controversy surrounding
the question of whether the tombstone of a war criminal should be given the status of a
protected monument. Another, similar, example can be taken from this same sector:
should bunkers and other products of a repressive regime be protected? Shouldn’t the
Berlin Wall have been a protected monument? The visual arts have constantly
presented us with such dilemmas down the centuries; overpaintings of naked figures in
various paintings are silent witnesses to this. By extension, we could ask ourselves
whether a masterly photograph, which also happens to be pornographic – or worse still,
could be regarded as an example of child pornography – should also be regarded as a
-17-
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
valuable part of our heritage. Famous photographers, as David Hamilton, Irina Ironesco,
Will McBride, Jock Sturges and Ron Olivier has produced photographs that are, by
some people, regarded as examples of child pornography, and by others as significant
and beautiful pictures that can not be forgotten or pushed away from our consciousness,
when we consider the history of photography. So taboos also enter into the discussion
surrounding musealisation and value study.
See also JANINE E. VAN REEKUM: Alienated appearances. Study of the relation between
the musealisation process and conservation. (Study for a Master’s Degree). Amsterdam
[Amsterdam School of Arts], 2000.
The Nara Document on Authenticity, 1994.
The Venice Charter 1964. International charter for the conservation and restoration of
historic monuments and sites.
The word interests is here again used in the sense referred to in § 5: i.e. the place that a
value occupies in the spectrum from priority to posteriority.
A.J. VAN BOMMEL, Restauratie-ethiek; in: Praktijkboek Instandhouding Monumenten 6
(July 2001), pp. 17 et. seq. (§ 5.1 De principe van de continue keuze).
VAN BOMMEL, 2001 op. cit. pp. 7 et. seq. (§ 3.4 Instandhouding).
Maxim 31 in: RUSKIN 1849 op. cit., p. 194.
THOMSON 2002 op. cit.
THOMSON 2002 op. cit., p. 40.
18 November 2002.
BERT VAN BOMMEL: Vlaardingse monumenten en stadsgezichten; in: Historisch Jaarboek
Vlaardingen, Vlaardingen [Historische Vereniging Vlaardingen], [1977…] 1998.
Dirk Roosenburg, born 1887 (The Hague), died 1962 (The Hague). See e.g. the
overview of his work in: GIOVANNI FANELLI: Moderne architectuur in Nederland 19001940, The Hague [Staatsuitgeverij], 1978, pp. 306-7. (ed. princ.: Architettura Moderne in
Olanda, Florence, 1968).
E.g. in the presentation by the Town and Monument Committee of the Historische
Vereniging Vlaardingen during National Heritage Day [Open Monumentendag] and in
the article ‘Monumenten van de Wederopbouw’ in: Musis 3 (1997) 9 (September).
Also incidentally housed in a not unattractive complex. The original complex, which was
built in 1952-56, was designed by Adrianus van der Steur and W.A.C. Herman de Groot
and, after their deaths, it was completed under the overall supervision of
architectenbureau Van Bruggen, Drexhage, Sterkenburg en Bodon. This bureau also
designed the extension that was built in 1969. See: K. ZITA MESSCHAERT (commissioned
by Vlaardingen town council): Inventarisatie vooroorlogse en naoorlogse bouwkunst
rivierzone Vlaardingen, Amsterdam, 2001, pp. 42-8.
K. ZITA MESSCHAERT: De Technische School; in: Tijdschrift 77 (September 2000), pp. 616.; see also: K. ZITA MESSCHAERT, 2001 op. cit., pp. 34-41.
The original demolition order was withdrawn and replaced by a conditional demolition
order: If the laboratory extension does not go ahead, the college will be saved.
This argument can be applied to all forms of heritage. What is, for example, the
authentic version of a novel? Is it the story as conceived by the author, the manuscript,
the first impression, the fifth revised edition or the updated modern version? Which is
the authentic Ninth Symphony by Ludwig van Beethoven, or the authentic Dying Swan,
or the authentic Dutch countryside?
Restoration. Both the word and the artefact are modern. To restore an edifice means
neither to maintain it, nor to repair it, nor to rebuild it; it means to re-establish it in a
finished state, which may in fact never have actually existed at any given time. EUGÈNEEMMANUEL VIOLLET-LE-DUC: Dictionaire Raisonné de l’Architecture Française du XIe au
XVIe siècle, Paris [B. Bance], 1854 (Translation: KENNETH D. WHITEHEAD: The
Foundations of Architecture. Selections from the Dictionaire raisonné, New York
[George Braziller], 1990, p. 195.) Thus, for example, let us take a building constructed in
the twelfth century without gutters for its roof drains, which had to be restored in the
thirteenth century and at that time was equipped with gutters producing combined
-18-
28.
29.
30.
31.
32.
33.
34.
drainage. The crowning is now in bad condition and has to be completely rebuilt. Should
the thirteenth-century gutters be abandoned in order to restore the cornice of the twelfth
century (of which the elements are all still present)? Certainly not. … Let us take another
example: the vaults of a twelfth-century nave were destroyed as a result of some kind of
accident and were then rebuilt later, not in their original form but in the typical form of
the time of the rebuilding. But now these later vaults, too, are threatening to collapse;
they need to be rebuilt. Should they be reconstructed in their later, remodelled form, or
should the earlier, original vaults be re-established? The latter. … KENNETH D.
WHITEHEAD 1990 op. cit., p. 211.
VAN BOMMEL, 2001 op. cit. p. 27 (§ 6.5 Gelaagdheid van authenticiteit (waarde)).
VAN BOMMEL, 2001 op. cit. pp. 26-7 (§ 6.5 Gelaagdheid van authenticiteit (waarde)): (1)
material authenticity, (2) conceptual authenticity (3) contextual authenticity (4) functional
authenticity (5) a-historical authenticity (6) historical authenticity and (7) advanced
historical authenticity.
Authenticity … appears as the essential qualifying factor concerning values. The Nara
Document on Authenticity, 1994.
When action to conserve a building begins, the one and only purpose behind the work is
to safeguard the site's value and to protect society's interest. The main aim is not the
maintenance of the fabric as is often thought, though maintenance is an essential part of
the process. The aim should be to protect the ‘cultural significance’ by maintaining the
fabric, to find a way of conserving the physical form which does the least damage to its
qualities under protection.
Some of the more valuable characteristics are very easily crushed. For example, if
historical evidence is tampered with or if the work of a unique and rare genius in art and
craft is ‘touched up’ by someone else however skilled, their greatest value may be
destroyed; the evidence is no longer reliable and the artistic merit is dulled. Through
loss of authenticity, the works themselves have become comparatively worthless even
though most of the fabric itself has been saved. D. BELL: The Historic Scotland Guide to
International Conservation Charters [Technical Advice Note 8], Edinburgh [Historic
Scotland], 1997, p. 27.
As a result, all changes, including the most recent, are ascribed authenticity. This
doesn’t mean that they should weigh as heavily in a consideration of interests as the
knowledge of an earlier situation, which is also part of the status quo. Denslagen
presents this problem as follows: When constructions from the recent past obtain the
value of historical monuments and are then restored, then there is usually no reason to
attach the same value to later changes, as referred to in Article 11 of the Charter of
Venice, because these changes do not yet represent any historic significance. This
Article does not therefore provide a sound basis for the restoration of twentieth century
monuments. A well-known example is the 'Zonnestraal' Sanatorium by J. Duiker (1928),
which was restored after the Second World War in such a way that its original character
was undermined. These recent changes have as yet so little historic importance for our
generation and the building’s original appearance from 1928 is still so familiar that a
reconstruction is to be preferred over the current situation. (W.F. DENSLAGEN: De
Charter van Venetië en de Monumentenconservatie in Nederland tussen 1964 en 1990.
In: Jaarboek Monumentenconservatie 1990, Zeist [Historic Monuments Agency], 1990,
pp. 30-5, p. 34. The underlining is not from the original article) I cannot myself endorse
this view, at least, not with the tone it adopts. It is not exclusively of importance whether
these recent changes are of historical significance for our generation, since our master
is the global community of all times. It is therefore also important what value future
generations could attach to it.
Vlaardingen, Smalle Havenstraat 23.
Consecrated on Easter Monday (28 March) 1910, designed by Tjeerd Kuypers (1857 1942) (M.A. STRUIJS: De Nieuwe Kerk, s.l., s.a.). In addition to the Nieuwe Kerk,
Kuypers also designed other buildings for Vlaardingen, including the Kuiperstraatkerk
-19-
35.
36.
37.
38.
39.
40.
(1904), which has since also disappeared. See also: H.P.R. ROSENBERG: De 19deeeuwse kerkelijke bouwkunst in Nederland, The Hague [Staatsuitgeverij], 1972, p. 101.
Freely after RUSKIN 1849 op. cit.
Modern twentieth century art historians appear equally unable to give a value-free
account. Even a leading scholar like Nikolaus Pevsner did not manage to keep his
devotion to the principles of architectural theory espoused by the Modern Movement out
of his historical analyses. W.F. DENSLAGEN: ‘Clio is ook een muze’. In: Jaarboek
Monumentenzorg 1990, Zeist [Rijksdienst voor de Monumentenzorg], 1990, pp. 9-16, p.
11.
This might also be regarded as a Form (eidos), as mentioned in note 7.
At the time of writing, a publication is being prepared in the Netherlands on this issue. A
working party on Veiligheid in kerken (Safety in historic churches) is considering this
topic at the request of the Rijksdienst voor de Monumentenzorg (Governmental Historic
Monuments Agency).
… it must be remembered that there is a vast difference between declarations of
principle and the practice of historic building conservation. … Situations can always
arise in which it is wiser to depart from the theoretical principle, for example because
there are greater interests at stake than only those pertaining to the conservation of
historic buildings. As the word itself suggests, a declaration of principle is an intention,
an agreement concerning the policy that people want to pursue. Between intention and
execution there is the inhospitable region of clashing interpretations and interests.
DENSLAGEN 1990 [Het Charter van Venetië…], p. 31. To what extent can a monument
be rebuilt for a new function without seriously undermining its historic value? This
question is now even more pressing than that of the ethics of restoration. The dangers
now threatening historic buildings are much greater – both in size and in significance –
than those that accompanied a nostalgic reconstruction and recreation of historical
stereotypes. … When demolition threatens, simply managing to find a building a new
function is already a considerable victory in itself, and you can’t then start imposing a
series of further requirements concerning the preservation of its integrity and the
restoration of its internal design and decoration. DENSLAGEN ibid. pp. 32-3. The author
does not believe that other interests, such as modern functionality, should be included
under the ethics of restoration. This is a view with which I must fundamentally disagree.
The approach to historic buildings is indissolubly linked to their treatment in
architectonic, urban planning, functional and economic terms. An ethics of conservation
which does not also concern itself with questions relating to these areas is not just bereft
of practical significance, it also ignores the influences that always help to define a
building, and through that limitation renders itself irrelevant. That is why I would
emphatically wish also to highlight those aspects of the ethics of conservation.
As mentioned earlier, the ethics of heritage conservation cannot be politically neutral.
Bert van Bommel is senior policy officer for historic building conservation at the Advice and
Architecture Directorate of the Government Buildings Agency. He is also editor of the
Praktijkboek Instandhouding Monumenten (Historic Buildings Conservation Guide) and a
member of the Vlaardingen town council Historic Buildings Committee.
-20-
DAS BRANDENBURGER TOR BETRACHTET AUS RESTAURIERUNGSÄSTHETISCHER SICHT
Stefan Grell, Caro Restaurierung und Technologie GmbH
1. Einleitung
Der vorliegende Beitrag soll neben der Information zu der kürzlich erfolgten Restaurierung zwei
wesentliche
Faktoren,
die
ästhetische
und
historische
Authentizität
in
der
Objektauseinandersetzung darlegen.
Während sich die historische Echtheit aus der Baugeschichte und hierbei insbesondere den
nachhaltigen Eingriffen in das Objekt ergibt, ist die ästhetische Echtheit von den natürlichen
Alterungsspuren abhängig. Sie sind die unverzichtbaren Bestandteile, die dem Objekt
historische Qualität und Würde verleihen.
Das Restaurierungsziel des Projekts BBT 2000 orientierte sich primär an Leistungen zum
langfristigen Erhalt des Objektes. Parallel galt es, die repräsentative Wirkung unter
Berücksichtigung sämtlicher Denkmalwerte wiederherzustellen.
Die Oberflächenintegrität, die durch den Einsatz modernster Reinigungstechnik eingehalten
wurde, und die Rückführung der Architekturablesbarkeit durch Homogenisierung der
Ergänzungsleistungen garantieren die historische und ästhetische Echtheit. Der vorliegende
Patinierungsgrad vermittelt sämtliche Denkmalwerte des 200 Jahre gealterten Objektes.
Die Diskussion um das optische Erscheinungsbild ist unter Berücksichtigung der
bauhistorischen Veränderungen zu führen. Hierfür sollen die Bauchronologischen
Veränderungen des Objektes anhand der Bau- und Restaurierungsgeschichte näher betrachtet
werden.
Das Restaurierungsergebnis soll seine Wirkung in unterschiedlichen Objekteindrücken
vermitteln.
Seit seiner Errichtung im Jahre 1791 durchlief das Brandenburger Tor eine wechselvolle
Geschichte, in der gesellschaftspolitische Ereignisse die inhaltliche Bedeutung des Gebäudes
veränderten. Über die Funktion als Stadttor erhielt es nach den napoleonischen
Befreiungskriegen die Stellung eines nationalen Siegestores. Aus dem Nationaldenkmal
entwickelte es sich während des kalten Krieges zum Symbol der deutschen Teilung.
Mit dem Fall des eisernen Vorhangs und der Wiedervereinigung erfährt das Tor auch
Bedeutung als ein Friedenstor. Neben der international hohen Rangstellung ist das
Brandenburger Tor als Wahrzeichen der Stadt das bedeutendste Bauwerk des Berliner
Klassizismus.
2. Bau- und Restaurierungsgeschichte
Das Brandenburger Tor entstand in den Jahren 1789 bis 1792 nach Plänen von Carl
Gotthard Langhans und ersetzte das alte „Thiergarten Thor“. Es ist das letzte erhaltene von
ehemals 14 Stadttoren und schloss das Berliner Zentrum nach Westen hin ab.
Als Vorbild für den Architekturentwurf dienten die Propyläen der Akropolis in Athen.
Zunächst entstand ein dreiteiliger Torbau, der sich aus dem Haupttor und zwei
freistehenden, nach Osten gerichteten Nebengebäuden zusammensetzte.
Das Haupttor, bestehend aus 12 Säulen, Architrav und Attika war mit einem umlaufenden
Metopenfries und einem großen Attikarelief im Osten nach Entwürfen von Johann Gottfried
Schadow gestaltet. Seitlich fügten sich kleinere, durch Pilaster gegliederte Flügelbauten an
die Stadtmauer an.
Östlich zum Pariser Platz hin entstanden zwei flachere Seitengebäude, die platzseitig von
Säulen flankiert wurden und an den Seiten unmittelbar an die hinter der Stadtmauer
stehenden Palaisgebäude anschlossen. Die Durchfahrten waren durch Holz- und Eisentore
verschließbar.
-1-
Das Gebäude erhielt zur Erbauungszeit einen weißen, marmorimitierenden Anstrich in Form
einer Kalktünche. Erst 1793 wurde die Quadriga aufgestellt.
Bereits im Jahr 1804 wurden die ersten Reparaturen notwendig, mit ihnen einhergehend
erfolgte ein neuer Anstrich in einer Ölfarbe, welche volkstümlich zu der Bezeichnung des
sog. „Caffee au lait“ führte.
In den Folgejahren 1816, 1840 und 1868 sind weitere Anstriche in variierenden Farbwerten
zwischen Grau und Ocker belegt.
Mit der Eingemeindung der Außenbezirke Moabit, Wedding und Teilen von Schöneberg und
Tempelhof im Jahre 1861 verlor die alte Stadtmauer an Bedeutung und wurde niedergelegt.
Aufgrund des nun fehlenden Anschlusses erfolgten in den Jahren 1867/68 an die
Seitengebäuden umfangreiche Umbauten.
Für die westliche Durchschreitung wurden großzügige Säulenhallen zwischen dem Haupttor
und den Flügelbauten hergestellt. Die beiden Standfiguren von Minerva und Mars wurden in
Nischenöffnungen der Säulenhallen integriert. Die eisernen und hölzernen Torflügel wurden
entfernt.
Abb. 1: Historischer Grundriss aus dem Jahr
1866
Abb. 2: Eduard Gaertner Ölgemälde 1846
Abb. 3: Theodor Rabe Ölgemälde um 1850
Abb. 4: Älteste historische Fotografie, vor
1865
-2-
Abb. 5: Historischer Grundriss nach 1868
Weitere Reparaturen des Bauwerks erfolgten in den Jahren 1875/76. Auf Veranlassung des
deutschen Kaisers Wilhelm II. wurde das Attikarelief 1897 mit einer Ölblattvergoldung
gefasst. Sie stellt die einzige farbige Absetzung der ansonsten monochromen Farbgebungen
im Laufe der Fassungsgeschichte dar.
Mit zunehmenden Bauschäden erfolgte im Jahr 1913 eine umfangreiche Voruntersuchung
und Bestandsaufnahme, die im darauf folgenden Jahr die notwendigen
Instandsetzungsarbeiten folgen lassen sollte. Aufgrund des 1. Weltkriegs und der Inflation
konnte die Restaurierung erst mit der Entwicklung der wirtschaftlichen Prosperität im Jahr
1926 beginnen.
Während der umfassenden Restaurierung in den Jahren 1926/27 wurde neben
umfangreicher Steinauswechselung gegen einen verwitterungsresistenten Sandstein die
Entfernung der im Objekt vorhandenen Farbreste angestrebt. Durch Empfehlung des
beteiligten Wissenschaftlers Prof. Rathgen sollten chemische Entfernungen unterlassen und
lediglich abgelöste Farbschollen mechanisch beseitigt werden. Zur farblichen Anpassung
der
neuen
Werksteine
an
die
patinierte
Bauwerksoberfläche
wurden
Magnesiumfluatlösungen und Ruß verwendet. 10 Metopenplatten mussten durch Kopien
ersetzt werden. Die Quadriga wurde umfassend restauriert.
Während das Tor bis in die letzten Aprilwochen 1945 weitgehend verschont geblieben war,
wurde es im „Endkampf“ um Berlin stark beschädigt.
Aus der Beobachtung der Kriegsschäden ist der gezielte Beschuss in Hinblick auf die
Zerstörung der Quadriga zu vermuten.
Massive Schäden erfolgten an den Hauptsäulen der Westfassade, wobei die dritte Säule bis
auf einen Restquerschnitt von ca. 10% reduziert wurde. Als Folge der Lastumverteilung
sackte das Architrav um ca. 10 cm ab. Großflächige Oberflächenverluste entstanden an der
zweiten und fünften Säule, die allerdings keine statischen Veränderungen der
Baukonstruktion zur Folge hatten. Auf der Ostfassade waren ebenso großflächige Verluste
an der ersten, dritten und sechsten Säule zu erkennen.
An den Seitengebäuden waren die Dächer und Dachstühle durch Brandeinwirkung
vernichtet worden. Große Bereiche der nördlichen Säulenhalle waren eingestürzt, die
Quadriga bis auf zwei Pferde und den Streitwagen zerstört.
-3-
Abb. 6: Gesamtansicht von Osten 1906
Abb. 7: Durchfahrbare Baustelleneinrichtung
1926/27
Abb. 8: Kriegsschäden am 2. Mai 1945
Abb. 9: Kriegsschäden am 2. Mai 1945
Erste Sicherungsmaßnahmen erfolgten unmittelbar nach Ende der Kampfhandlungen. Stark
zerstörte und einsturzgefährdete Partien des Bauwerks wurden mit Holzverbau gesichert.
Bis in den Juni 1945 wurden sämtliche Sicherungsmaßnahmen an den Säulen durch
Betonverfüllungen abgeschlossen.
Die Wiederaufbauarbeiten begannen im Jahre 1950 und konzentrierten sich auf das
Haupttor. Drei Metopen wurden vollständig erneuert, die Figuren aus den Seitennischen
restauriert bzw. kopiert. 1951 wurden die Flickstellen mit einer pigmentierten
Zementverschlämmung überdeckt. Das Wohnungsbauprogramm der Stalinallee im Zentrum
Ostberlins band jedoch in großem Maße die Baukapazität, so dass die
Wiederaufbauarbeiten bis 1956 unterbrochen waren. Mit der erneuten vollständigen
Einrüstung wurden die Wiederaufbauarbeiten 1956/57 abgeschlossen. Die seitlichen
Torhäuser des durch die starken Kriegszerstörungen freistehenden Tores wurden
umgebaut, die Brandwände zu den benachbarten Palaisbauten zurückgesetzt und jeweils
mit einer äußeren Säulenreihe versehen. Putz- und Sandsteinflächen wurden umgreifend
erneuert. Um die alten und neuen Sandsteine farblich aufeinander abzustimmen, wurden
alle Architekturteile mit einem Scharrierhieb überarbeitet und alle Verschmutzungen und
Farbschichten auf den Reliefs durch Ablaugen beseitigt. Entgegen der vorangegangenen
Restaurierungsleistungen wurde 1957 gezielt eine absolute Materialsichtigkeit hergestellt.
1958 wurde eine in Westberlin hergestellte Kopie der Quadriga auf das Tor montiert.
Mit dem Bau der Berliner Mauer spitzten sich die Rahmenbedingungen für die Erhaltung des
Tores weiter zu. Durch seine exponierte Stellung im Grenzstreifen zwischen Ost und West
war es von beiden Seiten sichtbar aber nicht zugänglich.
Zahlreiche Überlegungen und Pläne zu einer Generalrestaurierung wurden nicht
durchgesetzt. So erfolgten trotz Widerspruchs der Denkmalpflege in den Folgejahren
wiederholt Farbanstriche auf den Putzoberflächen. Weiterhin wurden partiell Erhaltungs- und
Erneuerungsmaßnahmen realisiert, die allerdings einzig dem optischen Gesamteindruck
dienten und denkmalpflegerische Überlegungen außer Acht ließen.
-4-
Anlässlich der 750- Jahrfeier Berlins wurden 1985 die Putzflächen instandgesetzt. Eine
umfangreiche Restaurierung, die anlässlich der 40- Jahrfeier der DDR geplant war, wurde
hinter der Instandsetzung anderer Prestigeobjekte zurückgestellt.
Abb. 10: Die Baustelle 1957
Abb. 11: Instandsetzung der Ostsäulen 1957
Abb. 12: Fertigstellung 1957 ohne Quadriga
Abb. 13: Das Tor im Grenzstreifen 1976
Durch die Öffnung der Mauer im Jahre 1989 wurde das Tor für den Verkehr wieder
freigestellt und erhielt kurzzeitig seine Funktion als Grenzübergang zurück. Mehr denn je
war es zum Symbol für die Teilung und Wiedervereinigung geworden und stand nun im
Mittelpunkt des öffentlichen und politischen Interesses. Eine umfassende Restaurierung und
Instandsetzung war nun unabwendbar geworden.
Anlässlich der 200- Jahrfeier des Tores sollte die Restaurierungsmaßnahme realisiert
werden. Grundlage waren die denkmalpflegerische Zielstellung ebenso wie die „kultur- und
gesellschaftspolitische Stellung“ des Objektes.
Neben den Schäden, die seit der Zeit des Mauerbaus entstanden waren, galt es nun auch,
die bei den Wiedervereinigungsfeiern entstandenen Beschädigungen zu beseitigen.
1990/91 erfolgten umfangreiche Sicherungsmaßnahmen, fachliche Voruntersuchungen,
Schadensund
Maßnahmendokumentationen
sowie
naturwissenschaftliche
Untersuchungen. Im Mittelpunkt der Maßnahmen stand die Reinigung der
Sandsteinoberflächen. Zahlreiche alte Ergänzungen wurden aus dem Objekt entfernt und
erneuert, ebenso erfolgten partiell Steinaustausch und die Putzerneuerung. Die Quadriga
wurde demontiert und vollständig restauriert.
Im Zuge der Neubebauung des Pariser Platzes ergaben sich Baugrundveränderungen, die
statische Schäden am Objekt verursachten. Die deutliche Verschlechterung des
Bauerhaltungszustandes forderte umgehend die erneute Restaurierung.
Mit dem Projekt BBT 2000 realisierte die Stiftung Denkmalschutz Berlin vertreten als
Bauherr die Restaurierung im Jahre 2000 bis 2002. Das neuartige freie Finanzierungsprojekt
ermöglichte die Restaurierung durch die Beteiligung eines Hauptsponsors ohne Verwendung
-5-
von öffentlichen Mitteln. Die Ausführung wurde an die Caro GmbH Berlin als
Generalübernehmer übertragen.
Abb. 14: Ronald Reagan 1987 am Tor
Abb. 15: Baustelleneinrichtung 1990/91
Abb. 16: Einhausung mit Werbeplane
November 2000
Abb. 17: Vorbereitung zur Enthüllung
September 2002
3. Die Restaurierung BBT 2000 bis 2002
Die im November 2000 begonnenen Restaurierungsarbeiten am Brandenburger Tor lassen
sich in die vier Themenbereiche Bestandserfassung, innovative Reinigungstechnologie,
restauratorische Verfahren und Festlegung einer verbindlichen Wartungskonzeption
gliedern.
Sie sind inhaltlich auf den neusten Stand bei der Objektauseinandersetzung ausgerichtet
und werden in der Objektanwendung eine langfristig anhaltende Wirkung für die
Restaurierungspraxis erhalten.
3.1. Bestandserfassung
Für die detailgenaue Bestandserfassung wurde eine dreidimensionale Vermessung
durchgeführt, die, kombiniert mit der Schadenskartierung, die Grundlage für die Planung der
Restaurierungsmaßnahme bildete.
-6-
Hierfür wurden ca. 500 DIN A3 Zeichengrundlagen in den Themenbereichen strukturelle und
Oberflächenschäden zeichnerisch erfasst und in ein virtuelles 3D-Modell überführt. Mit
dieser derzeit einzigartigen Objektdarstellung konnten alle Bereiche zusammenhängend in
einer Computeranimation betrachtet und für die Maßnahmenplanung überprüft werden.
Auch bei künftigen Wartungs- und Pflegemaßnahmen wird die abschließende
Maßnahmenkartierung die Grundlage der virtuellen Planung von Inspektionsfahrten mit dem
Skylift bilden.
Basierend auf den Schadenskartierungen lassen sich folgende Aussagen zu dem
Schadensbild und zur Schadensintensität treffen:
Die Bausubstanz des Brandenburger Tores befindet sich in einem weitgehend intakten
Erhaltungszustand.
25.000 kleinteilige sowie 3.500 großteilige Beschädigungen (Mörtelantragungen, Fehlstellen,
Vierungen) sind am Objekt vorhanden. Die Verteilung der Schadstellen fiel auf der
Steinoberfläche überwiegend gleichmäßig aus und ist auf die Kriegseinwirkung
zurückzuführen. Eine geringfügige Erhöhung an der westlichen Fassade ist mit der
intensiveren Bewitterung zu erklären.
Abb. 18-19: Das aus mehreren Standpunkten gemessene Punktwolkenbild ist mit einem 360°
Rotations- Laserscanner entwickelt worden. Das Punktwolkenbild stellt die Basis
für das 3D-Modell des Gebäudes dar. Mit dem Wechsel des Standpunktes für das
Messgerät erhöht sich die Dichte der Objektinformation, so dass über die
Verknüpfung der Scanneraufnahmen eine sehr hohe Genauigkeit erreicht wird.
Umfangreiche Schäden an der Verfugung und Rissbildungen im Naturstein waren durch
statische Veränderungen in Folge von Bautätigkeit in unmittelbarer Umgebung des Tores
entstanden. Zahlreiche bautechnische Mängel wie die fehlende gesteinstechnische
Anpassung der Ergänzungsmaterialien, Überdeckung von Bauwerksfugen, unzureichende
Maßhaltigkeit und vollständiger Verschleiss sowie die Verwendung von Betonmassen und
Ziegelmauerwerk als Hohlraumverfüllung erschienen korrekturwürdig.
Durch eine sehr unterschiedliche Oberflächenwirkung, die durch das Auseinanderaltern der
Ergänzungsmaterialien und der Originaloberfläche entstanden waren, litt das
Erscheinungsbild des Bauwerks erheblich. Darüber hinaus wirkten zahlreiche Vierungen in
Stapelverbänden mit dominanten Vierungsfugen sowie markant hervortretende
Mörtelreparaturstellen zergliedernd und verklärten die Architekturaussage des
klassizistischen Bauwerks.
Markante Verschwärzungen auf den der Hauptbewitterungsrichtung zugewandeten
Steinpartien wiesen auf tief in das Steingefüge eingelagerte Verschmutzungen, die in den
Regenschattenbereichen und Übergangszonen sogar in kompakte Gipskrusten übergingen.
Auffällig waren die z.T. flächenbegrenzten Intensitätswechsel der Verschwärzung im
Vierungsmaterial, die zudem durch die markanten Betonungen der Anschlussfugen verstärkt
wurden.
-7-
Abb. 20:
Attika Nordwest Westfassade: Abb. 21: Schadenskartierung I: Durch die
Auffällig zeigen sich die intensiv
farbige
Kennzeichnung
sind
schwarzen Steinoberflächen, die
kleinteilige
Fehlstellen
sowie
aus
der
Hauptbewitterungsgeöffnete Verfugungen zu sehen.
richtung aus Westen resultieren.
Im linken Quaderbereich ist ein
Reinigungsmuster
aus
der
Maßnahme von 1990/91 zu sehen.
Abb. 22: Schadenskartierung II : Es liegt eine
intensive
Schwarzfärbung
mit
variierenden Anlagerungs- mustern
vor.
Abb. 23: Endzustand mit Referenzfeld
Zahlreiche Mörtelergänzungen waren aus dem Steinuntergrund abgelöst. Insbesondere in
den Bewitterungszonen waren die Mörtelantragungen durch Oberflächenabsandung und
den Verlust der Retuschen gekennzeichnet. Die Ursache hierfür lag in der Verwendung von
sperrenden Bindemitteln bei vorangegangenen Restaurierungen. Die Mörtelkonfekte wiesen
eine enorme Härte auf und konnten aufgrund der fehlenden Anpassung auf die
Festigkeitswerte der Elbsandsteinvarietäten der Cottaer Vorkommen als objektunverträglich
angesehen werden. Die Oberflächenausbildung zahlreicher Antragungen wirkte zudem in
der Reliefwirkung störend und ließ die Nachstellung der Steintextur vermissen. Bei der
Freilegung der Mörtelflicke wurde die großzügige Fehlstellenausarbeitung durch
-8-
Trennschleifen und Kernbohren deutlich. Im Bereich der sanierten Verfugung war ebenso zu
beklagen, dass das ursprüngliche Erscheinungsbild des Pressfugenverbandes durch
Trennschleifen verändert wurde. Die vermutlich ehemals kaum wahrnehmbaren
Quaderfugen der Architravzone waren bei der Freilegung in den Quaderflanken als sehr
schmale Fugen deutlich zu erkennen. Diese wurden bis zu 2 cm Breite durch Trennschleifen
geweitet. Verwitterungszonen waren in den exponierten Fassadenbereichen der
Westfassade sowie in Spritzwasserbereichen oberhalb der Dachflächen anzutreffen. Ebenso
konnten als Problemzonen die bewitterten Säulenbasen angesehen werden. Aktive
Verwitterungserscheinungen waren kaum vorhanden, so dass die Wirksamkeit der
Festigungsmaßnahmen aus 1990/91 bestand. Generell konnte eine Schalenbildung durch
Überfestigung, welche durch die seinerzeit nur als Standartfestiger mit einer feststehenden
Gelabscheidungsrate erzeugt wurde, nachgewiesen werden.
3.2. Restaurierungsziel
Mit der Diskussion zur Farbigkeit des Objektes, die sich aus einer etwa100- jährigen
Fassungsgeschichte und einer etwa 100- jährigen Materialsichtigkeit des Objektes ergibt,
wurden kunstgeschichtliche, denkmalpflegerische und restauratorische Aspekte beleuchtet.
Der Architekturentwurf von Langhans sah vor, ein marmorweißes Stadttor im
klassizistischen Stil am Tiergarten zu errichten. Nachweislich kam ein marmorimitierender
Anstrich als Kalktünche zur Ausführung. Noch in zahlreichen zeitgenössischen Gemälden
und frühen Fotografien lässt sich eine sehr gleichmäßige und scharfkantige
Architekturoberfläche erkennen. Gliedernde Fugen und Quaderungen sind kaum zu
erkennen. Die Bauveränderungen des 19. Jahrhunderts, die Abtragung der Stadtmauer und
die Öffnung der Seitenflügel mit der Errichtung der Säulenhallen stellten gravierende
Eingriffe in die ursprüngliche Konzeption dar. Das Tor erhielt in dieser Zeit einen
ockerfarbenen, sandsteinimitierenden Anstrich. Der Wunsch, die ursprüngliche weiße
Farbgebung zurückzuführen, würde die zeitgeschichtlich erfolgte Bauveränderung nicht
respektieren und der gesamten Architektur eine Oberflächenerscheinung geben, die keinen
authentischen Bezug hat.
Abb. 24: In den Aufnahmen ist ein Langrelief des Herkules-Zyklus aus den Torwangen
dargestellt. In der Abfolge der deckungsgleichen Aufnahmen lassen sich die 3DInformationen mit der fotorealistischen Textur sowie den zeichnerisch erstellten
Schadenskartierungen erkennen. Das Relief weist überwiegend großteilige
Ergänzungsmörtelstellen an den Verankerungspunkten der Relieftafeln auf. Die
Fugengrenzen
sind
deutlich
zu
erkennen.
Mit
der
stärkeren
Verschwärzungsintensität auf den jeweils rechten Figurenhälften ist die
Hauptbewitterungsrichtung aus Westen definiert.
-9-
Fassungsreste befinden sich in geringer Anzahl in tiefliegenden Regionen.
Verwitterungserscheinungen sind nicht vorhanden.
Für das Restaurierungsziel muss aus denkmalpflegerischen Gründen die Materialsichtigkeit
für den 1957 maßgeblich veränderten Baukörper angestrebt werden. Aus der
Bauchronologie ist ersichtlich, dass mit dem Errichten der zusätzlichen Säulenkolonaden an
den ehemaligen Baugrenzen zu Haus Liebermann und Haus Sommer eine
Materialsichtigkeit bestanden hat, die mit keiner historischen Fassung des Objektes
übereinstimmt. Ferner ergab die steinmetzmäßige Abarbeitung der Bauwerksoberfläche eine
gravierende Veränderung des Erscheinungsbildes. Die sehr unregelmäßigen Werkspuren
vermittelten nicht mehr den Charakter der glatten Oberfläche eines klassizistischen Baus
und stellen somit keinen geeigneten Untergrund für eine, dem historischen Zustand
entsprechende Farbgebung dar.
Zum langfristigen Erhalt des Objektes unter Beibehaltung des erreichten
Restaurierergebnisses ist eine Konservierung der Objektoberfläche erforderlich.
Eine Wasserabweisung durch Imprägnierungsmaßnahmen kann aus bauphysikalischen
Gründen nicht umgesetzt werden. Beschichtungen, die unter dem Aspekt der Opfer- bzw.
Verschleißschicht denkmalpflegerisch und restauratorisch einen sehr wirkungsvollen Schutz
darstellen würden, müssen aus ästhetischen Gründen sowie aufgrund des unklaren
Wartungsaufwandes abgelehnt werden. Zudem würde das gewohnte Erscheinungsbild des
Tores infolge dieser Behandlung entscheidend beeinträchtigt werden. Ferner müssten
mittelfristig Aufwendungen für Erneuerungsmaßnahmen inkl. der erforderlichen
Gerüststellungen berücksichtigt werden.
Auch aus restauratorischen Gründen ist die Beschichtung der Natursteinoberflächen nicht
sinnvoll, da sich insbesondere an den westlichen Säulenoberflächen überfestigte
Steinzonen befinden. Die hier nachgewiesene Schalenbildung wäre einer zusätzlichen
Belastung ausgesetzt und mit der Gefahr einer großflächigen Ablösung von Beschichtung
und Steinoberfläche verbunden.
Abb. 25: Attika Südwest Vorzustand
Abb. 26: Attika Südwest Endzustand
Abb. 27: Attika Südwest Mittelrisalit
Vorzustand
Abb. 28: Attika Südwest Mittelrisalit
Endzustand
-10-
Die Anforderungen an die Restaurierung des Tores lassen sich folgendermaßen
zusammenfassen: Primär muss durch die Reinigung die Rückführung der
gesteinsphysikalischen Parameter erreicht werden, d.h. die gleichmäßige Aufnahme und
Abgabe von Wasser gewährleistet sein. Ferner ergibt sich mit dem Anspruch auf
Wiederherstellung der Ablesbarkeit und der ästhetischen Präsentation, dass tiefgründige
Verschwärzungen, die sich vornehmlich an den westlichen Fassadenoberflächen befinden,
mittels Lasertechnologie entfernt werden müssen. Sämtliche Maßnahmen, die zum Erhalt
des Objektes erforderlich sind, beinhalten die Erneuerung und Korrektur von schädigenden
Altleistungen. Desolate Oberflächenzustände müssen mit geeigneten Verfahren erneuert
werden. Damit das Objekt unter Beibehaltung sämtlicher Denkmalwerte im Kontext der
Neubebauung des Pariser Platzes seine Würde zurückerhält, muss eine Homogenisierung
der gesamten Baustoffoberfläche erreicht werden. Dieses beinhaltet, dass das Fugenbild
und die Quadergliederung zugunsten einer klareren Architekturaussage zurückgeführt
werden müssen. Schließlich muss ein schlüssiges Wartungskonzept mit einem verbindlichen
Pflegeplan die Grundlage für den langfristigen Erhalt des Restaurierergebnisses bilden,
damit die Kostenminimierung für den Bauerhalt auch auf längere Sicht gewährleistet ist.
3.3. Restaurierungsmaßnahmen
Viele Untersuchungsergebnisse aus der Maßnahme 1990/91 wurden bei den
naturwissenschaftlichen Untersuchungen berücksichtigt und in die Planung der laufenden
Restaurierung mit einbezogen. Von maßgeblichem Einfluss auf das Erscheinungsbild war
der Einsatz der neuen Reinigungstechnologie. Die seit der letzten Restaurierung in 1990/91
erheblich verfeinerten Verfahren mit Mikrotrockenstrahl- und Lasertechnik stellten in der
Kombination eine Innovation dar, die zur Homogenisierung der gesamten
Architekturoberfläche beitrug. Alle tiefgründigen Verschmutzungen wurden mit der
Lasertechnik bearbeitet, die als berührungsfreie Reinigungstechnologie bei definierten
Energiedichten die Oberflächen bis zu mehreren Kornlagen tief schadensfrei reinigen
konnte. Für den Einsatz des Laserreinigungsverfahrens war die Festlegung der
Reinigungsparameter erforderlich. Um sicherzustellen, dass keine Objektveränderungen in
Form von laserinduzierten Schäden eintreten, wurden naturwissenschaftliche
Untersuchungen zur Lasertechnologie durchgeführt. Hierfür wurden für die verwendeten
Natursteinarten in unterschiedlichen Expositionen Musterflächenbereiche angelegt, die
mittels Rasterelektronenmikroskopie ausgewertet wurden. Die hierbei ermittelten
Energiedichten wurden während der Maßnahme durch regelmäßige Kontrollmessungen der
Geräte überprüft (Powermeter).
Zahlreiche Mörtelantragungen aus der Maßnahme in 1990/91 wiesen erhebliche
Überschreitungen der tolerierbaren Druckfestigkeit auf, so dass eine umfangreiche
Erneuerung durchgeführt werden musste. Hierbei wurden die Neuantragungen mittels
Pigmentzusätze auf den Farbwert der jeweiligen Oberflächen eingestellt. Mit der Ergänzung
mit durchpigmentierten Ergänzungsmörteln ist eine langfristige Ästhetik auch gewährleistet,
wenn diese zurückwittern bzw. mit neuen Reinigungsmaßnahmen überarbeitet werden
müssen.
Die gesamte Verfugung des Objektes wurde erneuert, da sich umfangreiche Fugenschäden
durch statische Bewegungen ergeben hatten und der Bestand an Verfugungen aus 1957 als
älteste Fugmaterialien geschädigt bzw. verschlissen war. Für den Ersatz wurden
insbesondere durchpigmentierte Fugmörtel verwendet, die aufgrund der angepassten
Druckfestigkeitswerte keine Schädigung der Steinflanken erbringen und sich in ihrer
Farbwirkung nicht gliedernd auf die Architekturoberfläche wirken.
-11-
Reinigungsmuster Laser
Abb. 29: Musterflächenbereich der Abb. 30: In der Rasterelektronenmikroskopischen
westlichen Attika - Aus
Abbildung
ist
die
mit
dem
den Testflächen, die mit
Laserverfahren gereinigte Oberfläche
unterschiedlichen
dargestellt. In der sehr hohen Auflösung
Energiedichten des Lasers
können laserinduzierte Schäden in Form
bearbeitet wurden, wurden
von Mikrorissen und Kantenausbrüchen
Proben
für
die
an
den
Quarzkornoberflächen
Materialanalyse
ausgeschlossen werden, womit eine
entnommen.
Objektveränderung nicht gegeben ist.
Die Erneuerung von Steinvierungen erfolgte grundsätzlich unter der Vorgabe, dass die
Fehlstellenbereiche nicht vergrößert wurden. Zum Austausch gelangten desolate Vierungen,
Vierungen mit abweichenden gesteinstechnischen Merkmalen und Vierungen, die über
Fugenbereiche gelegt waren und die Gefahr der Kantenpressung mit dem Verlust von
Originalsubstanz beinhalteten. Für den Neueinsatz wurden Ersatzmaterialien, die
weitestgehend auf die historischen Abbauhorizonte der Steinbrüche im Elbsandsteingebirge
zurückgreifen, verwendet. Hierbei wurde auch das Kriterium der Farbgebung berücksichtigt,
so dass dem jeweiligen Ausgangsstein nahezu identische Materialien zugeordnet werden
konnten und somit langfristig eine gleichmäßige Alterung von Original und Ergänzung
gewährleistet ist. Sämtliche Bearbeitungsspuren, die sich aus der steinmetzmäßigen
Überarbeitung des gesamten Objektes in 1957 ergeben haben, wurden in die neuen
Vierungen übertragen. Stapelverbände wurden weitgehend zusammengelegt und durch
einzelne Vierungen, die dem Fehlstellenverlauf folgen, ersetzt. Sämtliche bildhauerischen
Oberflächen wurden neben der Oberflächenreinigung in dem Restaurierergebnis von
1990/91 belassen. Geringfügige Überarbeitungen ergaben sich aus abgelösten
Ergänzungen bzw. Rissbildungen im Fugenverlauf.
Die Putzoberflächen der Wachhäuser und Torwangen wurden mit einem neuen Anstrich
versehen, der in der Farbwirkung auf den neu erreichten Reinigungsgrad des Objektes
abgestimmt wurde. Es zeigte sich, dass der 1990/91 aufgebrachte Silikatdispersionsanstrich
abgenommen werden musste, da er für die Neubeschichtung nicht mehr tragfähig war. An
den Wachhäusern mussten in geringfügigem Maß Ausbesserungen an durch statische
Bewegung verursachten Rissbildungen und Putzablösungen vorgenommen werden.
-12-
Abb. 31
Abb. 32
Abb. 33
Attika West Quaderreihe C-E im Vor-, Zwischen- und Endzustand
Abb. 34
Abb. 35
Abb. 35
Säule West 3 Trommel C im Vor-, Zwischen- und Endzustand
3.4. Pflegeplan
Da eine Wasserabweisung der gesamten Objektoberfläche nicht umgesetzt wurde, müssen
für die exponierten Objektoberflächen Wartungsleistungen berücksichtigt werden.
Wasserabweisungen durch Imprägnate können am Brandenburger Tor wegen der
unterschiedlichen Steinmaterialien nicht eingesetzt werden, da mit den sehr stark
variierenden Schutzstoffmittelaufnahmemengen vorzeitiger Verschleiß und eine
Teilhydrophobie im Objekt zu riskanten Oberflächenzuständen führen kann. Beschichtende
Materialien, die gleichzeitig eine Materialsichtigkeit des sehr lebendig gebänderten
Natursteinmaterials zulassen, müssten aufgrund der kurzfristigen Standzeiten zu
regelmäßigen Erneuerungsmaßnahmen und ständigen Kontrollen führen. Inwieweit hierbei
ästhetische Beeinflussungen in der Materialidentität vorliegen und Bänderungen des
Natursteins künstlich nachempfunden werden müssen, würde sich insbesondere bei der
Alterung als problematisch erweisen.
Längerfristige Beschichtungen, die zusätzlich Verschleißschichtcharakter beinhalten würden,
können dem Anspruch der Materialsichtigkeit nicht gerecht werden.
Wartungsleistungen bzw. Erneuerungsintervalle mit erneuten Gerüststellungen wären
innerhalb von 10 Jahren vorzusehen. Letztendlich würden diese nicht dem Anspruch auf
Reversibilität
gerecht
werden.
Die
mit
der
Objektübergabe
eintretende
Wiederverschmutzung muss unter einer erheblich verbesserten Luftqualität beurteilt werden.
Der Grad an Verschwärzungsintensität, der aus einer 40 jährigen Entwicklung unter einer
stark rauchgasbelasteten Atmosphäre entstanden ist, würde vermutlich erst wieder in 60-80
Jahren ohne eine erneute Reinigungsmaßnahme eintreten. Der Anteil an Mikroorganismen,
die auch an der Verschwärzung des Objektes beteiligt sind, ist hierbei unklar zu bewerten,
da dieser Faktor veränderten Wachstumsbedingungen unterliegt. Aus der Objektbeurteilung,
dass in der gereinigten Oberfläche keine gravierenden Veränderungen seit 1957 an der
Oberfläche eingetreten sind und die Textur der Steinbearbeitung unverändert vorliegt, kann
das Objekt ohne Endkonservierung belassen werden.
-13-
Abb. 37: Deckblatt für den Wartungsplan
Staubdeposition
in
Regenschattenbereichen,
Schmutzeinlagerung
in
den
regenzugewandten, kapillar saugenden Steinflächen müssen bei der Wartung berücksichtigt
werden. In Form von Zwischenreinigungen an ausgewählten Objektbereichen wird das
Restaurierergebnis nachhaltig erhalten bleiben, ohne dass eingreifende Maßnahmen in das
Objekt (Hydrophobierung) vorgenommen werden müssen. Insbesondere müssen die
Objektbereiche mit Überfestigungszonen der Originalsubstanz in Verbindung mit einer
Beschichtung beobachtet werden. Der Verlust der mechanisch zusätzlich belasteten
Oberflächen ist grundsätzlich nicht auszuschließen. Erneute Reinigungsleistungen werden
mit der naturwissenschaftlichen Untersuchung von Probesteinen geplant, die an den
Hauptbewitterungsbereichen des Objektes ausgelegt werden.
Mit dem Pflegeplan müssen, kurzfristig beginnend, folgend in größeren Zeitintervallen
kontinuierliche Inspektionen durchgeführt werden. Diese werden sich aus Sichtprüfungen
aus dem Bodenniveau und Skyliftfahrten ergeben.
Sämtliche bei der Restaurierung erstellten und alle belassenen Leistungen müssen hierbei
auf ihre Funktionsfähigkeit überprüft werden.
Generelle Wartungsleistungen zum Bauerhalt wie z.B. die Überprüfung von Verblechung,
Dachentwässerung und Fallrohren sollten auch durch Begehungen des Objektes nach
längerem Regen durchgeführt werden.
Hierbei soll die Art und Entwicklung von Oberflächenverschmutzungen ermittelt werden, um
die Intensität der Reinigungsverfahren und deren Zeitintervalle langfristig abzuschätzen. Für
die kritischen Überfestigungszonen werden Konservierungsflächen als Musterbereiche
angelegt die regelmäßigen Sichtprüfungen und naturwissenschaftlichen Beprobungen
unterliegen. Mit den regelmäßigen Inspektionen der Bauwerksoberfläche werden
auftretende Schäden frühzeitig erkannt und, mit der Planung und Reparatur, Folgeschäden
und -kosten vermieden.
-14-
4. Zusammenfassung
Gegenstand
der
restauratorischen
Bearbeitung
war
eine,
durch
die
Wiederaufbaumaßnahmen von 1956/57 veränderte Bauwerksoberfläche.
Mit der Reinigungstechnologie konnten die verklärenden Oberflächenerscheinungen
nachhaltig beseitigt werden, so dass der Patinierungsgrad die natürlichen Alterungsspuren
des Objektes präsentiert. Mit der schadensfreien Bearbeitung verbindet sich ein hohes Maß
an Objektintegrität.
Der zum Erhalt der Bausubstanz notwendige Austausch von Ergänzungsleistungen wie
desolaten Vierungen, Mörtelantragungen und Fugen wurde unter dem Aspekt der
langfristigen ästhetischen Wirkung umgesetzt. Die auf den Patinierungsgrad der
Steinoberflächen angepassten, durchpigmentierten Mörtel sowie die materialidentischen
farbneutralen Ersatzsteine gewährleisten langfristig eine kontinuierliche ästhetische
Wirkung. Sie berücksichtigen auch erneute Reinigungsmaßnahmen und die Alterung der
Objektoberflächen.
Die Entscheidung, die Objektoberfläche ohne eine Endkonservierung zu belassen, wird
durch die denkmalpflegerische und restauratorische Bewertung und die Realisierung des
Wartungskonzeptes mit dem verbindlichem Pflegeplan getragen.
Abbildungsverzeichnis:
Historischer Grundriss aus dem Jahr 1866
Eduard Gaertner 1846
Theodor Rabe um 1850
Älteste historische Aufnahme vor 1865
Historischer Grundriss nach 1868
Gesamtansicht von Osten 1906
Durchfahrbare Baustelleneinrichtung 1926/27
Kriegsschäden am 2. Mai 1945
Kriegsschäden am 2. Mai 1945
Die Baustelle 1957
Instandsetzung der Ostsäulen 1957
Fertigstellung 1957 ohne Quadriga
Das Tor im Grenzstreifen 1976
Ronald Reagan 1987 am Tor
Baustelleneinrichtung 1990/91
Einhausung mit Werbeplane November 2000
Vorbereitung zur Enthüllung September 2002
Punktwolke 1
Punktwolke 2
Foto Attika Nordwest
Kartierung I Attika Nordwest
Kartierung II Attika Nordwest
Foto gereinigte Attika Nordwest
Langrelief des Herkules- Zyklus
Foto Attika Vorzustand
Foto Attika Endzustand
Foto Attika Vorzustand
Foto Attika Endzustand
Laserprobefläche
REM- Aufnahme
Attika Vor-, Zwischen und Endzustand
Säule Vor-, Zwischen und Endzustand
Caro Pflegeplan
aus: Arenhövel, S. 49
aus: Laabs, S. 46
aus: Laabs, S. 50
aus: Arenhövel, S. 35
aus: Arenhövel, S. 49
aus: Arenhövel, S. 51
aus: Laabs, S. 76
Foto Museum Berlin-Karlshorst
aus: Cullen, S. 84
aus: Laabs, S. 107
aus: Arenhövel, S. 157
aus: Arenhövel, S. 158
aus: Arenhövel, S. 311
aus: Arenhövel, S. 314
aus: Arenhövel, S. 171
Foto DSM, Megaposter Neuss
selbst
IB Dr. König
IB Dr. König
selbst
selbst
selbst
selbst
IB Dr. König
selbst
selbst
selbst
selbst
IBW, Weimar
IBW, Weimar
Caro GmbH
Caro GmbH
selbst
-15-
Literaturquellen:
- Arenhövel, Willmuth / Bothe, Rolf: das Brandenburger Tor 1791-1991, Berlin 1991
- Cullen, Michael S./ Kieling, Uwe: Das Brandenburger Tor - ein deutsches Symbol, Berlin
1999
- Laabs, Rainer: Das Brandenburger Tor – Brennpunkt deutscher Geschichte, Berlin 2001
- Stiftung Denkmalschutz Berlin (Hrsg.): Das Brandenburger Tor- Weg in die GeschichteTor in die Zukunft, Berlin 2002
Beteiligte Firmen:
CARO Restaurierung und Technologie GmbH, Berlin
Ochsenfarth Restaurierungen GmbH, NL Berlin
Nüthen Restaurierungen GmbH & Co. KG, Erfurt
Bennert Restaurierungen GmbH, Hopfgarten
CARE! Technology NovaPlast GmbH, Berlin
APC AG, Nürnberg
Tisch Gerüstbau GmbH, Berlin
PlaNus GmbH, Berlin
Dipl.-Rest. Stefan Grell, Berlin
IB Gerlach & Vavva GbR, Berlin
MmA Multimediale-Archivierung GbR, Berlin
IB Dr. König, Potsdam
WSI Weßling & Schmitt Ingenieurgesellschaft mbH, Berlin
GSE Ingenieurgesellschaft mbH, Berlin
PSS Interservice GmbH, Berlin
Caparol GmbH& Co.KG,
Remmers Bauchemie GmbH, Löningen
Naturwissenschaftler:
Herr Dr. Goretzki
IBW, Weimar
Herr Dr. Wilimzig
WIQOM, Hamburg
Herr Dr. Altenberger
Uni Potsdam Institut für Geowissenschaften Arbeitskreis
Mineralogie von Baustoffen, Potsdam
Herr Dr. Hilbert
Remmers Bauchemie GmbH ZOA, Löningen
Herr Prof. Dr. Riederer SMPK, Rathgen- Forschungslabor, Berlin
Herr Dr. Pfefferkorn
IDK, Dresden
Herr Dr. Laue
IDK, Dresden
Frau Dr. Ehling
Bundesanstalt für Geowissenschaften und Rohstoffe, Berlin
Herr Dr. Bagda
Deutsche Amphibolin-Werke, von Robert Murjahn GmbH & Co.
KG, Ober- Ramstadt
Herr Dr. Erfurth
IBB GmbH, Welden
-16-
HERITAGE AND ATTITUDE
Jo Coenen, Rijksbouwmeester
Abstract
It is my strong belief that my profession – design – is based on continuity. This principle has
been strongly impressed on my mind, and I learned it by constantly familiarising myself with
what our forefathers studied and built. Even the greatest innovators throughout history have
adopted the idea of continuity as a key tenet.
In my presentation I discuss a number of contemporary currents of thought that approach
this idea in different ways. In doing so, I distinguish four attitudes.
Attitude one. The first attitude abides by the motto of breaking with history and sees the
‘’incompatible”, the “unharmonious”, as exciting and challenging. The conflict itself becomes
the fundamental purpose of the design.
Then there is a second current of thought which, rather than breaking with an existing
building, wishes instead to speak to it and to its original context. I refer to this attitude as
dialogue. One example of this is a proposal to extend the Palace of Justice in Leeuwarden.
Henning Larsen has added a building in cross-section with a transitional element. You can
see by the façade that he is trying in his sketch to continue a horizontal line and hence to
mirror the segmentation, to repeat the echo of the roof and to reflect the lobby in the floor
plan. It strikes me as so highly articulated in its proportions and dimensions, that despite the
different materials being used, a dialogue is trying to emerge.
Congruence, another interesting theme-as-attitude: a step further, becoming part of the
same assembly.
Here’s an example from Amsterdam: a new building erected between the old canal houses
that form this overall image. If you half shut your eyes, you can see a continuity, a
congruence of sizes and proportions. Despite the fact that it is a contemporary building, it
wants to fit in, to harmonise. The setting is complete. It is very nicely done.
The last and most difficult attitude is that of merging and amalgamation: a higher level of
attitude, in fact. We begin way back in history with the Villa Hadriana. The Emperor Hadrian
had his stonemasons and bricklayers reproduce buildings he had encountered on his
travels. They managed this so cleverly that they created out of them a coherent entity whole.
As a result, the various components melt together in spite of the different fragments that
stand for different symbols of things. That is the attitude. From Hadrian to Francesco
Venezia.
-1-
CULTURAL DURABILITY, CULTURAL SUSTAINABILITY
Anne Malliet, dienst Vlaams Bouwmeester
bOb Van Reeth, Vlaams Bouwmeester
1. Introduction
Since his appointment, the Flemish Government Architect bOb Van Reeth has considered to
aim for architectural quality in government assignments in Flanders by devoting attention to
sustainability. Building industry is placing an increasing burden on the environment and this
is a good reason to fundamentally rethink architecture. Sustainability and sustainable
building are new challenges for architecture, which will re-source construction, and generate
new buildings and new designs.
The conservation of historical buildings is a discipline which can make an important
contribution to this search for sustainable building. After all, the department for the
conservation of historical buildings has experience with buildings that last, with what bOb
Van Reeth defines as “cultural durability”. “Cultural sustainability” is the key concept which
the Flemish Government Architect would like to introduce in the debate on architecture. With
the concept of “cultural sustainability” he aims to expand the debate and liberate it from the
common discussions on ugly versus beautiful. In fact, the architectural debate is still
concerned too much with purely formal and aesthetic matters and this applies to training, as
well as welfare commissions, architectural critics, and the policy for the conservation of
historical buildings. An environmental awareness and the demand for sustainability will add a
different content to the debate. It should become a discussion on concepts of sustainable
urbanisation, sustainable architecture, sustainable buildings, concepts which mean that the
environmental burden created by building is significantly reduced.
2. Intelligent ruins
A concept of sustainable architecture cannot do without concepts related to quality, such as
permanence, rigidity, versatility, but also deals with something that appears to be
contradictory to this, that is: the ability to change. Builders must invest and commission
buildings which will last several generations, and architects have to design these buildings. It
is important to make a distinction between the location, the site and the footprint of a
building, as well as its structure or skeleton. These elements should have a long-term
character. They should be designed in such a way that there is no need for demolition in the
next four hundred years. On the other hand, there are the arrangements in the building, the
finishing and the technical systems, which have a much shorter-term character and should
therefore be designed and created as such. This is the concept which the Flemish
Government Architect refers to as an “intelligent ruin”.
3. Sustainable concepts
A sustainable building requires a structure with a great degree of autonomy in relation to the
specific building programme of the commission. In a sense, the functional programme of
requirements should serve only as the reason or alibi for the sustainable building. Buildings
should not only comply with today’s requirements, but they should reveal adaptability and a
capacity for change. Today we have to make buildings in a way that they can also be useful
for the spatial requirements of tomorrow. We have to realise that building requirements of
today often become out of date very soon, sometimes even before the building has been
completed. So the question is: what makes buildings last? What makes buildings adaptable
to new generations. History has provided us many examples.
-1-
Sustainability in architecture concerns the whole complex process. It concerns the process
that makes that building and rebuilding becomes an act of culture. Buildings which are
recognised for their cultural value and significance acquire as such a lasting character. This
sustainability produces added value, which grows over the course of time. Experience has
shown that if this results in buildings of which we do not have to be ashamed in the next fifty
years, they will be cherished for the next three hundred and fifty years, and will be looked
after as historical buildings. Therefore, if we wish to build buildings that last, we have to
design buildings that will acquire a place in the cultural memory, and as we do so this will
ensure them a long future.
According to the Flemish Government Architect, the search for architecture is the search for
these concepts. The Flemish Government Architect has introduced the instrument of Open
Call for this search for sustainable concepts.
In fact, Open Call is a procedure to select designers for architectural commissions of the
Government of Flanders. The principle of the Open Call is that five agencies are selected in
the first round. In this selection we search not only for quality but also for diversity with
regard to the approach and the vision on architecture. These five teams are assigned a
limited task of developing a preliminary vision and concept for the building contract being
offered. In the second round, one design team is then selected on the basis of the presented
vision and approach, and the contract is assigned to that team. With this procedure the
Flemish Government Architect hopes to encourage the search for architectural quality and
design. It shows that there is often more than one good solution for a building assignment.
In most cases the Open Call produces five completely different ideas. And this is something
the building authorities often didn’t expect. The client usually benefits from this rich variety of
solutions to his questions.
4. Projects from “Open Call”
I would like to illustrate today’s topic with three projects from the Open Call: three different
locations, three different buildings for which we used the Open Call to find design teams to
develop a concept, a long-term vision for an architectural problem. As my time for this
lecture is limited, I can only show you the winning concept for each location. They are all
related to the architectural heritage. All three concern existing, lasting concepts or buildings.
Cultural sustainability requires a sustainable approach to this heritage. These projects
concern also the maintenance and the restoration of the existing buildings. But in these
projects restoration is not an isolated aspect. It is not the only goal. These are projects in
which the demands of today and tomorrow have been integrated and this resulted in what
we interpret as sustainable concepts, concepts for the future with a respect for the past.
4.1. The Opera House in Antwerp: architects, Paul Robbrecht and Hilde Daem
Of the five proposals which resulted from the Open Call, this was the most innovative
proposal, and at the same time, the proposal which revealed the greatest care and concern
for conservation of the existing building. The masterplan of the architects Robbrecht &
Daem appears to tackle the questions posed by the opera house of Antwerp, with its existing
infrastructure and unique opportunity for expansion, in the most feasible and at the same
time, in the most ambitious way.
The Antwerp Opera House was built between 1904 and 1907, in accordance with the design
of the city architect, Alexis Van Mechelen. The special character of this opera building is that
it is conceived as a house in a row. The most prestigious opera houses in Europe are
autonomous, free-standing buildings on beautiful public squares. Opera houses are rarely
incorporated in the structure of a block of buildings. From 1905, the architect Emiel Van
Averbeke was also involved in the construction of the opera house, and on the basis of his
design, a building was added on the corner. The opera café is situated on the ground floor
of this building, and there is a warehouse for the storage of sets on the upper floors of this
-2-
majestic corner building. A splendid rehearsal area was also designed within the structure of
the roof of the building.
Between this corner building and the opera house there are two private town houses. This
means that the connection between the opera house and the café and the storage area for
sets was not a simple matter. There is a connecting corridor from the opera to the café on
the ground floor, and props and sets have to be pulled up a slope into the warehouse and to
the entrance of the set. However, there is now a unique opportunity to demolish the two
houses in between, and rebuild the lot for the opera house. This means that it will be
possible to create room for offices, staff accommodation, a foyer for the artists, and a new
rehearsal area. At the same time, the plan is to adapt the stage and the additional stage
along the lines of the recently renewed infrastructure in the Gent opera house. After all, the
Flemish Opera operates in both cities and puts on every production in both opera houses.
In the case of a free-standing opera house, expanding widthways is a problem. The
exceptional advantage of the situation in Antwerp is the possibility to create space in this
unique location. In the area between the stage and the storage space there is room for new
facilities, for accommodations for which there was no need at the time the opera was build.
This is an opportunity, and the architects have made full use of it. They are building a large
and powerful new building on the liberated site and are taking the opportunity to achieve a
high density level of construction there. At first sight it seemed obvious to fill up the empty
plot with a functional service and office area, and to cover the new building with a curtain
wall to create some light between the three separate walls. Robbrecht and Daem suggest
instead to create an exceptionally large additional stage on the ground floor of the building.
The new work areas and the artists’ foyer are planned above this in a huge new roof
structure on top of this massive lower building. For the offices and the staff area the
functional proximity to the stage is not the absolute priority. In fact, it is the presence of light
and air that is important. Light and air are limited in the lower part of the building, but the
elements are present to an almost unlimited degree in the roof-area. As a result of the
ambitious vision of the new building, it was also possible to create an additional rehearsal
space under the new roof. This option made it no longer necessary to divide up the storage
area with floor structures for office space. The building, with its beautiful structure of
studded pillars, is no longer used nowadays for storing sets. But it can still be useful as
storage space for the mobile concert enclosure, which makes that the stage can be adapted
for concert performances. Because of this ingenious design, the character of both the opera
house and the storage area can be retained, and actually used to their full potential. A
respect for the existing structures goes hand in hand with the contemporary additions.
Another fascinating aspect is the fact that the solution is closely related to the character and
identity of the existing structure. On the one hand, the new building has a completely new
and individual identity, but at the same time it is also very closely related to the nineteenthcentury concept of the buildings, in particular the character of a massive lower structure, with
a large roof in the form of a steel structure superimposed on this. The way in which the new
building reinterprets the basic components of the existing house with it’s massive lower
structure and the imposing - but light - roof structure, is familiar in some ways, but
nevertheless adds a new dimension.
This is a sustainable design. It presents a spatial concept, based as far as possible on what
is available and the way in which this can be used, while at the same time creating as much
room as possible for the additional accommodation and the improvement of the technical
infrastructure of the theatre. This concept really does add a significant contemporary
dimension to the structure of the existing opera house. The plans are not on a larger scale
than the plot of the town houses to be demolished, and yet the opera house will be
substantially expanded, and will therefore lead to significant improvements in the future in
technical opera and theatre terms. At the architectural level this expanded opera house will
also acquire an international reputation.
-3-
4.2. Deurne Airport: architects: Baumschlager + Eberle + Grassmann from Austria in
collaboration with FDA, Antwerp
The airport building of Deurne near Antwerp dates from 1929, and was built for the world fair
in Antwerp in 1930. The building designed by the Brussels architect Stanislas Jasinski was
the result of an architectural competition.
At the time in Antwerp it was an extremely modern building. Renaat Braem, who was just
twenty years old, described it as a unique achievement in architecture. He was over the
moon about the fact that this very modern building was commissioned by the state and
about the beauty of the building. Beauty which he defined as – and I quote- “inherent in
every organism that serves its purpose” –end of quote. And for architecture to him this
purpose was to find –and I quote again- “the solution of using space in the most functional
and economic way to serve society”.
With the Raphael project of the European Community, attention was devoted to the surviving
European airports from the pioneering years of civil aviation. The airport building of Deurne
is not only one of the earliest airports in Europe with such a modern design, but is also one
of the best surviving examples from the pioneering period. In fact, this is due to the
stagnation of activities at the airport and the fact that the airport has always operated on a
small scale. This means that the arrivals building was not replaced or unrecognisably
transformed as so many others have been. Admittedly the building has not remained intact:
some of the windows were renewed, the interior was substantially rebuilt, and obviously the
increased safety measures required many modifications. In 1951, the old control tower was
replaced by a new one. However, the design and structure of the building were largely
maintained.
The reasons for the request for a long-term vision in the Open Call include the necessary
modifications in connection with the Schengen agreements, which require separate facilities
for Schengen and non-Schengen passengers. There was also a realisation that some of the
recent rebuilding and expansion activities were injurious to the architectural and historical
value. Jasinski’s design shows this building with an L-shaped ground plan, with a central
arrivals hall in the angle, and an open space three levels high. The area for passengers was
in the left wing, ending in café and restaurant with a roof terrace on the upper floor. The
section on the right accommodated the services for goods transport connecting to the
hangar. On the floors there were offices for the airport personnel and the central command
post or control tower. The glazed passage which provided access to the hangar from this
floor, so that the flight equipment could be inspected, was an absolute first in the design at
the time. This complete structure and the roof light above the central hall were also
important, and contributed to the ease of identification of the airport from the air. The planes
were not yet controlled with radio contact at that time, and the pilots were dependent for
navigation on their own vision and on maps.
Although the building is not yet a listed monument, all five design teams for the Open Call
based their designs on the value of the architectural quality and the historical value of the Lshaped building, and on considerations of conservation and renovation.
As regards the urban context, the design of the architects, Baumschlager and Eberle, is
based on the current location and spatial organisation of the access from the Luchthavenlei.
The design includes completing the square in front of the airport building on the site where
the current situation creates an unfinished impression. On that side, the square in front of the
airport building will be bordered by a multi-storey car park, ending in an office wing on the
side of the square. There are plans for the construction of a hotel to complete the triangular
block of buildings in the angle of the Luchthavenlei and the Diksmuidelaan.
The design is based on stripping all additions and transformations to regain the original
passenger hall. The later expansions are of no architectural value and will also be removed.
The purpose of the original frighthangar as a storagebuilding or a utilitarian area is no longer
self-evident in that location. All the recent airplane hangars are located elsewhere on the
airport site. The space in the original passenger hall is too small to accommodate both
departures and arrivals as it was in the past. So in the future the original hall will serve only
-4-
as a departures hall. So the nearby space of the former hangar is most suitable for the new
arrivals hall. In order to regain the passenger hall to its former spatiality and lightness, a lot
of inbuild officespace will have to be removed. This means that new office space is required,
and the plan is to replace the old hangar by a new office building, a tower block with the
same footprint as the hangar.
The coherent spatial solution for both the representative public buildings, and for the more
utilitarian additional buildings of Jasinski’s design, means that the airport can now be
adapted to the growing demand for space. However, the old hangar was badly damaged
during the Second World War, and of the original structure, only the façade with the sign
"Luchthaven" (Airport) and the side wall on the land side have survived. The segmented iron
structure of the roof, the back wall and the wall on the runway side date from after the war.
As the competition programme explicitly provided, the airport building had to allow for future
growth. Jasinski responded to this with the design of the hangar, which could be extended
with modules of 50 metres each. The mobile back wall was also designed with this purpose
in mind. In fact, the hangar was never extended.
Now the former hangar can provide a solution for the shortage of space in a different way
from that anticipated in 1930, though in a way that is still strongly related to this. With this
design, this historically interesting witness of the early years of civil aviation, this wellpreserved airport from the pioneering period, can be preserved as a functional
airportbuilding for the future.
4.3. Hoge Rielen, Kasterlee, Studio 02, Bernardo Secchi and Paola Vigano
The Hoge Rielen is a youth centre managed by the Government of Flanders, and located on
a site in the Antwerp Kempen. The site was developed during the 1950s as the British Arms
Depot III, as part of the NATO activities. After being used for ten years, the whole
infrastructure of forty identical sheds and more than 9 km of concrete paths was preserved in
an enclave of woodland, heath land and peat areas.
In the 1970s, the Government of Flanders bought this area so that it could be used by youth
groups as a camp site and for outdoor pursuits. For this purpose, many of the sheds were
rebuilt and renovated in the course of time. Modifications were made to many of the
buildings in accordance with the ideas and needs at the time. In some cases the sheds were
transformed beyond recognition. As a result, the uniformity and character of the site were
lost to some extent.
With the Open Call an attempt was made to establish a long-term vision, a master plan for
the continued use and development of the site. In particular, there should be a guideline to
determine the quality of the visual aspects and design of the new accommodation to be
planned and the buildings to be renovated. The proposal of Studio 02 corresponded best to
our expectations.
The proposal is based on the vulnerable character of the military heritage. The military
architecture and the organisation of the site have defined and structured the landscape, but
these traces can easily be erased. The recent modifications have illustrated this all too
clearly. Therefore Studio 02y considers that these elements need to be protected, and
propose an intelligent approach which respects the character of this heritage.
The military sheds are utilitarian buildings, simple and functional, and constructed with
limited materials and means. The roof is made of a light steel structure, and the thin brick
walls are reinforced with a steel framework. Every shed was originally surrounded by a
safety mound, and there was a concrete reservoir for water to extinguish fires in the
immediate vicinity. The safety mounds and wells have already been overgrown by
vegetation and levelled to the ground in some places, and have therefore disappeared.
These are vulnerable elements which can only be protected with extra care and
maintenance. As regards the approach to the sheds, there are three types of intervention,
which are all based on maintaining the simple utilitarian character of the existing buildings.
They are based on the simple conclusion that these sheds were not built to be inhabited,
and that making them habitable means that it would be necessary to put in windows and
-5-
openings for light. This would inevitably change the spirit of the buildings and the character
of these constructions, which is not the intention.
The three proposed possible ways of rebuilding the sheds respectively concern the low,
moderate or higher level of comfort to be provided. The bare military shed is an outside area
that is covered over, a simple hall, which can serve as temporary accommodation, a
protected area for a campsite, if it is properly maintained and modestly equipped. With this
moderate equipment the shed becomes a comfortable “stone” tent, which can be useful for
events, sport, music, theatre and debate. With slightly better facilities, more light, temporary
heating, the provision of water and sanitary facilities, the shed can be used more intensely
and for longer periods. If a shed is to be habitable all year round, this will not be sufficient.
For that sort of use, the plan is to make use of a wooden box, a thermally insulated and
completely equipped module. This box is a modular structure that can be placed in the
building, next to the building or outside it. It can be used as a single element, but boxes can
also be linked together to make clusters. It is a prefabricated building element which adds to
the existing building what is lacking in the construction, and does so in a way that is
reversible. It has its own character and does not detract from the identity of the existing
utilitarian character of the military constructions.
5. Conclusion
We believe that these examples illustrate what sustainable concepts are. Sustainable
restoration concepts are intelligent measures which respect the qualities of the existing
structures while providing a long-term vision. I believe that these examples also reveal that
respecting authenticity means that the questions of the use of the architectural heritage
today and in the future have to be approached in a sensitive and intelligent way.
All three examples concern twentieth-century buildings which are largely in their original
state. In the case of the Opera House with its storagebuiling, as well as the airport building of
Jasinski, and the military remains in the Hoge Rielen, we are confronted with very authentic
structures in the sense that no significant building campaigns have taken place in the past
century. For all three examples, the original design and the original construction are valued
as being authentic. The refurbishments and adaptations that have occurred in the past were
all ad hoc modifications which did not add any intrinsically valuable elements. For all three,
we have today clearly formulated an ambition that what we do today should add for the first
time a significant building campaign to the existing site.
For our older heritage, authenticity is not such a straightforward matter. In most cases there
is a more complex history, and an “irreversible” layer was added to the building in nearly
every century. These modifications are often not only “irreversible” in terms of technical
restoration, but they are irreversible above all because they are valued today as a sign of
their time, as a valuable buildingperiod. Cultural sustainability is searching for concepts that
have these lasting qualities. In the century before conservation of historical monuments
became an issue, the approach to the architectural heritage was obviously a lot less
restrained. Elements were demolished and rebuilt particularly in relation to the demands and
requirements for space at the time. What remained was usually conserved only because it
represented some economic value as a build space, or sometimes simply as building
materials. Nowadays we weigh up the work of our predecessors for its cultural value and try
to make our own modifications with a certain understanding and insight. This of course will
benefit the intrinsic value of the contemporary restorations and refurbishings, though we
believe that this will not be sufficient in its own. We believe that today’s interventions also
should have character and identity. Therefore the building commission must be clearly
formulated. Cultural sustainability should be the ambition. In addition to respect towards our
architectural heritage, there should also be a response to today’s requirements which looks
to the future and takes spatial and formal qualities into account. In accordance with Braem’s
definition we could say it is “the solution of using space as well as material and hence also
our build heritage, to serve it not only in the most functional way but also in a cultural durable
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way, to serve it not only in an economic but also in an ecological way, to serve society not
only today but also tomorrow”.
Therefore, we believe that restorers and designers should cooperate because the
conservation of the architectural heritage is more than a goal in itself. It always entails a
good solution for the use to be made of a historic building. A knowledge of the history of the
building is a precondition for this, together with a sensitivity to the individual character and
value of the heritage, but the vision for the use of the building today and tomorrow is just as
essential. We hope the projects you have seen make clear what this approach can be.
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FROM CONSERVATION PRINCIPLES TO MATERIALIZATION
(Or the other way around: how is materialization guided by principles?)
Koenraad Van Balen, K.U.Leuven
On sabbatical leave to: Getty Conservation Institute, Los Angeles
1. Introduction
Craftsmen, architects, engineers, historians and policy makers involved in the process of
conservation of the architectural heritage have to face many choices when starting to
execute works, plan conservation or define priorities in the conservation of the architectural
building stock.
We have contributed to the debate on the relation between conservation principles (based
on the concepts of authenticity) and the contribution to conservation interventions. Those
contributions [12, 4, 11, 1] (e.g. the discussion on external requirements for the study of
historic mortars in view of their repair) approached that relationship from principles in the
direction of applications.
The experience gained with the making of an expert system for assessment damage to
historic brick masonry structures [2, 9, 10, 8] is useful to reverse the approach. We thought
that instead of going from abstract conservation principles towards the materialization, we
could turn things around and try to define the lines of choices faced by practitioners. This
paper tries to develop a goal-oriented way of thinking about this matter. It is a challenge to
translate some of the more abstract concerns developed earlier into an approach directed to
professionals that are more likely to “do the job”. Using the concept of decision tables, being
used for the development of the Masonry Damage Diagnostic System, and other types of
experts systems we will try to define what are the conditions required to reach a certain
solution or knowledge.
To make things clear and more concrete with examples, we assume a certain situation: a
craftsman is asked to re-point an historic and important heritage building. Although we use
the word ‘craftsman’ we do not intend to limit this concept to masculine persons nor to give
any evaluation whether such workmanship should preferentially done by one gender then
another. We found that using the word ‘craftsperson’ just sounds more ‘artificial’.
He has to do the job, and being concerned about the authenticity of the fabric, he will need
input from others and evaluate a variety of alternative solutions. Let’s try to tackle the
problem from his viewpoint and make clear what reasoning should be involved.
Of course in real life and in general terms we shouldn’t accept such a procedure where
’action’ is requested without holistic and complete understanding based on preliminary
investigations. We hope that through the proposed reasoning the nature of such a holistic
approach will also become clearer.
2. The “baggage” of the craftsman and his contribution to preservation
The craftsman has a valuable baggage to tackle a job, and that should be considered first.
With baggage we mean the things the craftsman can carry with him being: his tools, his
knowledge, his background, ... Trying to describe it allows us to define its strength and its
limits.
“Our” craftsman is in the first instance a human being and we might expect that he feels
being part of the (civil) society that understands that maintenance of the heritage is about
preserving a collective memory and that actions related to that are important. He might have
learned this through his education at school, at the company where he works, in his family
and hopefully through involvements in his neighborhood or in societies aiming at the
preservation of heritage. All of these conditions might not apply but it certainly helps to get
the proper understanding of the values of heritage. Education and involvement thus are
-1-
conditions that impact the way our craftsman deals with and assesses values of heritage.
He might therefore choose to acquire education and involvement.
Our craftsman has learned a craft. It took him time and effort to acquire skills and
understanding, and he definitively wants to use it for his well-being and that of the society,
and why not for the heritage of his society? By learning the skills, he became aware that he
could express himself and be creative through this skills and therefore he considers that this
kind of work is different from routine work. It is a challenge for him to be creative, to
challenge solutions and to seek for the quality in what he is doing. It is not the easy way, but
people express their admiration for his work, for the challenges that he took and brought to a
good end. He really can be proud of his work. He gets satisfaction from maintaining his
skills and all relevant documentation of it.
However he requires enough opportunities to develop those skills and therefore needs
substantial practice in real cases. The maintenance of his skills (and of others) thus
depends on the number of occasions offered to the craftsman to apply his skills in
preservation works as well as in works on more recent buildings. If we accept that keeping
and transferring skills is essential to contributing to the preservation of the heritage, it means
that such skills are part of the heritage. This leads to a possible paradox that if material
conservation should be able to conserve all materials this would lead to the loss of skills,
endangering the possibly necessary intervention in the future.
In a wider sense the preservation of skills and know-how contribute to the “stock” of possible
sustainable building solutions. They contribute to the maintenance of a wider diversity of
ways of building and, in this way, to sustainability.
Out of what do those skills exist? They are based on the instruments the craftsman is
using, old and new tools that require particular handling based on training and experience.
His skills include knowledge on recipes and working methods.
This includes
understanding of various materials and practices he has been practicing and that gave –
according to him- satisfactory results. He is used to using certain materials and certain
sources of materials that, through his experience, provide better results than others.
Making proper selections of tools, mixtures and materials have taken him a lot of time. His
expertise is built on know-how, experience, and practice and therefore a good craftsman
knows what can be done and how things could be done.
Our craftsman’s concern for doing the right job makes him also wonder whether his
understanding of what is a good practice, what is a good recipe, what is a good material, etc.
are correct when dealing with the conservation of the heritage. Not only his concern about
execution and his input of all his skills should be taken into account. He will request input
from others whose advice he will need to make sure other aspects are covered which he
can’t judge. On the other hand he will be able to give feedback suggestions given to him, as
he can judge the possible effect of those suggestions on the way works can be carried out.
A list of conditions that should be fulfilled to allow the craftsman to really contribute to the
preservation of the heritage can be summarized as such:
- He needs training, education, application of his skills, rewards and recognition,
- He needs instrumentation, access to proper materials,
- He needs understanding of heritage values, longevity and values.
- He might need involvement in heritage preservation.
The basic dimensions of his contribution to the heritage will be
- a personal devotion and engagement;
- a skilled execution of conservation works;
- feed-back to his advisors on the practicality of the advices he was given;
- the preservation of the skills (a heritage value) through materialization of his skills and
through training aiming at transferring his knowledge to next generations.
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3. The craftsman’s contribution to preserving authenticity
The work carried out by the craftsman should contribute to the preservation of the heritage in
different ways. Further material degradation should be stopped, the workmanship should
survive, the appearance of the building should enhance its historic and artistic value, and his
work has to contribute to the improvement of the setting of the building in its (historic)
environment. These are a few concerns that make clear that his contribution forms part of a
wider picture.
Modern conservation practice uses the International Charter for the Conservation and
Restoration of Monuments and Sites (The Venice Charter [13]) from 1964 as a basis for
defining the way of treatment of historic buildings and sites. Many later charters and
documents developed at the international level, most of them worked out in collaboration
between UNESCO and experts from ICOMOS, have been gradually clarifying the
interpretation of that Charter for different types of applications or considering the need for
proper understanding in a different cultural context. We can name only a few as the
Australia ICOMOS Charter for the Conservation of Places of Cultural Significance (The
Burra Charter, 1981, Australia ICOMOS), The Charter for the Protection and Management of
the Archaeological Heritage (1990), The Nara Document on Authenticity [5].
Important issues in the debate are the understanding of the different cultural concepts of the
heritage and the understanding of the variety of values attributed to that heritage. Those
reflections lead to defining a more appropriate understanding of the input of our craftsman’s
skills in the preservation of the tangible and the intangible aspects of the heritage than was
the case in the Venice Charter.
Using the scheme proposed by the Nara document on authenticity a table was made that
can be read as a checklist to help identify different dimensions and aspects that cover the
values attributed to the architectural heritage.
ASPECTS/DIMENSIONS
Artistic
Historic
Social
Scientific
Form and design
X
X
X
X
Materials and substance
X
X
X
X
Use and function
X
X
X
X
Tradition, techniques and workmanship
X
X
X
X
Location and setting
X
X
X
X
Spirit and feeling
X
X
X
X
A checklist
Table 1: Based on Nara Document [5]
The craftsman will be able to take responsibility for some of those aspects and he will
require preliminary information and guidance on issues that relate to work of others or that
have to deal with more general concerns.
We have tried to summarize his input in this scheme in table 2. Some issues have been
dealt with in the previous paragraph when the “baggage of the craftsman” was discussed,
but a number of aspects are not completely in his hand and he will need input from others
(they are conditions to his intervention).
-3-
In table 2 it can be noted that we couldn’t find any examples of the contribution of our
workman to aspects such as “use and functions”. Maybe some examples could be found but
we couldn’t define them at this stage. Therefore, we accept at this stage that other people in
the decision chain will take complete responsibility and contribute with their expertise in this
matter. For some, aspects vs. dimensions input from other disciplines and decision makers
can be identified.
ASPECTS/
DIMENSIONS
Artistic
Form and design
Skilled
Appearance is
contribution to influenced by
artistic
historic
expression
understanding
of skills
Materials and
substance
Choice of
materials and
procedures
influence the
original artistic
expression but
also the
craftsman’s
new
expression
X
Understanding
and mastering
historic skills
and materials
are within the
conservation
of the material
and the skills
themselves
Tradition, techniques (Some) artistic
expressions
and workmanship
require
(traditional)
workmanship
that need
transfer of
skills over
generations.
Location and setting Artistic quality
of
craftsmanship
influences the
relation
between the
object and its
environment
X
Spirit and feeling
Historic
research in
historic
workmanship
contributes to
the survival of
it as an
intangible
heritage
Preservation of
historic skills
is a way to
preserve the
option of
generating
historic
settings
X
Use and function
Historic
Social
Contribution of
society’s
member to
visible
expression of
heritage
preservation
X
Scientific based
support is required
for skilled
execution
influencing the
appearance
X
X
X
Scientific
investigation of
materials gives
input into choice
of materials and
practices to the
craftsman
(Groups of)
Scientific
craftsmen are investigation gives
proud to be
insight to
contributing to
procedures and
the preservation workmanship and
of the heritage
allow evaluation
with
of the contribution
workmanship
to preservation
Involvement of
craftsmen (e.g.
gardener) in
conservation and
maintenance
make the setting
more accessible
to public
X
Table 2: Contribution of craftsmen
-4-
Scientific
X
X
4. Conditions for the craftsman
What kind of information, guidance and advice (these are the conditions) will the craftsman
need to fully contribute his skills to the proper preservation?
- Availability of materials on the (specialized) market;
- Information related to the buildings history and the historical dimensions of workmanship
and the appearance of the intervention he is requested to carry out;
- Information related to the buildings artistic dimension where generally the input of the
craftsman is part of a wider appearance of the historic building.
- Scientific input related to the materials and procedures that could affect the compatibility of
old or new interventions and to assure sustainable preservation.
For each of the above conditions input can be described as coming from various disciplines.
These disciplines will have to give in a concerted way the necessary advice that eventually
will be discussed with the craftsman.
Let us consider the last, more technical aspect as this might interest more of the audience of
the WTA.
According to the draft documents made within the Technical Committee of Rilem (Réseau
International des Laboratoires des matériaux) the latter conditions can be fulfilled if advice is
given on technical requirements that lead to defining recipes and intervention methods.
Those requirements on their turn are conditioned by the functional requirements that relate
the technical requirement within the technical role for example pointing plays into the setting
of the building. Again the general understanding that rules technical issues as dealing with
choices of materials or treatments are conditioned by the concepts of retreatability and
compatibility [7], which are driven by the more general concept of understanding
authenticity. This representation as a chain of command is however not correct, as it is
linear. More cyclic models have been developed and argued allowing for interdisciplinary
input and collaboration, as is the case in Searls [6] and for structural repair in Lemaire [3].
Those models do start from a more general holistic understanding with an “analysis or
anamnesis’ phase. This includes a many sided in-depth investigation, leading to a synthesis
that aims at defining preservation objectives in the phase of “diagnosis”. This phase on its
term leads to the intervention phase named “therapy” followed by a phase that aims at
evaluating effectiveness of therapies in a “control”-phase. The different phases are however
connected with possibilities to loop backwards when missing information is identified or new
(unexpected) information comes to light. Here is where our craftsman -we almost forgot
him- has an important role. Although he is almost chronologically coming to the end of the
process, he should be involved in the different phases of the process. His skills and possible
ways of intervention will be decisive in the final result. They will have to be subjected to
evaluation using eventually the concepts of authenticity.
5. Conclusions
The devotion and input of a craftsman can make a significant difference in the way the
authenticity of the architectural heritage is preserved. He contributes to the intangible
aspects and dimensions of values of the heritage.
To define an intervention that materializes the preservation of the authenticity of the
architectural heritage, conditions can be defined that assure the dialogue between the
various disciplines involved into the process. That process should assure that partial
interventions fit into a holistic understanding of the values of the heritage.
Using the concept of decision tables that defines in a goal oriented way the necessary
conditions to assure a proper action, we have attempted to trace back the contribution of the
craftsman’s materialization of his skills on the conservation principles.
-5-
6. Acknowledgments
Thanks to Eric Bruehl, research assistant at Getty Conservation institute for the revision of
the text.
7. References
1. CASSAR, M., P. BRIMBLECOMBE, T. NIXON, C. PRICE, C. SABBIONI, C. SAIZ
JIMENEZ, and K. VAN BALEN. (2001) "Technological Requirements for Solutions in the
Conservation and Protection of Historic Monuments and Archaeological Remains."
Editor M CASSAR. EP/IV/A/STOA/2000/13/04. European Parliament, DG for Research,
Luxemburg.
2. FRANKE, L., I. SCHUMANN, R. VAN HEES, L. VAN DER KLUGT, S. NALDINI, L.
BINDA, G. BARONIO, K. VAN BALEN, and J. MATEUS. (1998) Damage Atlas,
Classification of Damage Patterns Found in Brick Masonry. Protection and Conservation
of European Cultural Heritage, Research Report European Commission, N°8, vol.2.
Stuttgart: Frauenhofer IRB Verlag.
3. LEMAIRE, R. M., and K. VAN BALEN, Editors. Stable - Unstable? Structural
Consolidation of Ancient Buildings. Monumenta Omnimodis Investigata. Leuven: Leuven
University Press, 1988.
4. NALDINI, S., R. VAN HEES, M PILAR DE LUXAN, F. DORREGO, K. VAN BALEN, R.
HAYEN, L. BINDA, and G. BARONIO. (2001) "Historical Pointing and the Preservation
of Its Value." in Structural Studies, Repairs, and Maintenance of Historical Buildings, VII,
Ed. C. A. BREBBIA, pp. 671-80, Southampton (UK): WIT Press.
5. NARA (1994),Nara Conference on Authenticity in Relation to the World Heritage
Convention, held at Nara, Japan, 1994.
Conference on Authenticity in Relation to the World Heritage Convention. Bergen,
Norway 31 January-2 February 1994. Trondheim: Tapir, 1994. 138 pp. ISBN 82-5191445-0
6. SEARLS, C. L., L. BINDA, J. F. HENRIKSEN, P. W. MIRWALD, A. NAPPI, C. A. PRICE,
K. VAN BALEN, V. VERGÈS-BELMIN, E. WENDLER, and F. H. WITTMANN. (1997)
"Group Report: How Can We Diagnose the Condition of Stone Monuments and Arrive to
Suitable Treatment Programs?" Saving Our Architectural Heritage: the Conservation of
Historic Stone Structures. Eds N. S. BAER, and R. SNETHLAGE, pp. 199-221.
Chichester: J. Wiley and Sons Ltd, 1997.
7. TEUTONICO, J. M.; CHAROLA, A. E.; DE WITTE, E.; GRASEGGER, G.; KOESTLER,
R. J.; LAURENZI TABASSO, M.; SASSE, H. R., AND SNETHLAGE, R., (1997) "Group
Report: How Can We Ensure the Responsible and Effective Use of Treatments
(Cleaning, Consolidation, Protection)?” Dahlem Workshop on Saving Our Architectural
Heritage: Conservation of Historic Stone Structures, Baer, N. S. and Snethlage, R.
(Eds), Chichester, John Wiley & Sons, pp. 293-313
8. VAN BALEN, K., and R. VAN HEES. (1995) "Expertensystem Für Die Beurteilung Van
Verfallserscheinungen an Historischem Ziegel-Mauerwerk." Instandzetsung Von
Mauerwerk, Editor E. NIEL, pp.1-18. WTA Schriftenreihe, Heft 6Aedificatio Verlag.
9. VAN BALEN, K., L. BINDA, R. VAN HEES, and L. FRANKE. (1996) "Damage to Historic
Brick Masonry Structures, Masonry Damage Diagnostic System and Damage Atlas for
Evaluation of Deterioration."Proceedings of the 8th International Congress on
Deterioration and Conservation of Stone, pp.1687-93.
10. VAN BALEN, K., J. MATEUS, L. BINDA, G. BARONIO, R. VAN HEES, S. NALDINI, L.
VAN DER KLUGT, I. SCHUMANN, and L. FRANKE. (1999) Scientific Background of the
Damage Atlas and the Masonry Damage Diagnostic System. Protection and
Conservation of European Cultural Heritage, Research Report European Commission,
N°8, vol.1. Luxemburg: Office for Official Publications of the European Communities.
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11. VAN BALEN, K., R. HAYEN, S. NALDINI, L. VAN DER KLUGT, R. VAN HEES, M. P.
LUXAN, F. DORREGO, and L. BINDA. (2001) "Mortar Characterisation, From Values to
Compatibility." in Maintenance of Pointing in Historic Buildings: Decay and Replacement,
Final Report, EC Environment Programme. Editors R. VAN HEES, S. NALDINI, and L.
VAN DER KLUGT, 75-84. contract ENV4-CT98-706
12. VAN BALEN K., I. PAPAYIANNI, R. VAN HEES, L. BINDA, (2003) External
Requirements, paper contributing to the activities of the RILEM TC “analysis of mortars
in view of their repair”, to be published
13. VENICE CHARTER (1964) International Charter for the Conservation and Restoration of
Monuments and Sites, 1964. (Web site:
http://www.icomos.org/docs/venice_charter.html)
-7-
COMPATIBILITY BETWEEN SAFETY AND AUTHENTICITY:
THE EXPERIENCE OF NOTO CATHEDRAL
L. Binda, A. Saisi, Politecnico di Milano
Abstract
The partial collapse of the Cathedral of Noto required a choice for repair and reuse of the
Church which seems to be in contrast with the preservation of the authenticity of the
monuments.
Nevertheless, a number of difficult problems, from social to safety, suggested to choose the
way of reconstruction of the lost parts. The paper describes the on site and laboratory
investigation carried out on the remaining parts of the Noto Cathedral, in order to verify their
state of conservation in view of the reconstruction.
1. Introduction
On March 13, 1996, the Cathedral of Noto suddenly partially collapsed, after being damaged
by the 1990 earthquake which hit the eastern part of Sicily (Figure 1).
After the collapse discussions took place on the possible solutions as a remedy to the
serious loss. Among them the community choose the reconstruction of the collapsed parts
with local traditional stones similar to the ones used for the construction of the Cathedral.
This decision supported by some experts in conservation and despised by others was and is
still the occasion of discussion and the level of the preservation principle.
The extensive experimental and numerical investigation carried out after the removal of the
ruins by a team of experts together with the designers [1], [2] clearly showed that the
collapse started from the pillars (one or more), due to the damages they already
accumulated before the earthquake.
Taking into account the extreme weakness of the collapsed pillars, the designers asked for a
further careful investigation on the remaining pillars of the central nave which also where
damaged by the collapse. The first idea was to repair and preserve these pillars during the
reconstruction of the Cathedral. The paper describes the on site and laboratory investigation
carried out and how the designers had to take the decision of demolishing them. Once again
this decision was considered wrong by the supporters of conservation and it is still discussed
with alternative answers pro and against.
2. The collapse and the decision for reconstruction
On December 1990 an earthquake hit the Eastern part of Sicily damaging old and
contemporary buildings in different towns. Noto, known as the “Baroque city” was among
them and several of its most beautiful buildings were seriously damaged. Also the Church of
St. Nicolò, the Cathedral, had damages to the vault, the lateral domes and to the pillars,
apparently no more than other buildings. Provisional structures and scaffoldings were set up
to support the damaged parts waiting for the repair and strengthening intervention. The
partial sudden collapse (Figure 1) occurred on March 13, 1996 fortunately without any
casualty and left the Noto community astonished by the loss of one of its most famous
buildings.
The church (Figure 2) had been built in different phases from 1764 over a previous smaller
church opened in 1703 to the public and demolished in 1769/70 as the new Cathedral was
growing. The Cathedral was opened in 1776. In 1780 the dome collapsed, was rebuilt and
the church was reopened in 1818. In 1848 the dome collapsed again under an earthquake
and then it was rebuilt and the church reopened again in 1862 but the dome was not
-1-
completely finished until 1872. In 1950 the Cathedral was restored with new renderings and
paintings and the timber roof substituted with a concrete structure; the work continued until
1959 [3].
Figure 1: The Cathedral after the collapse
Figure 2: The Cathedral before the collapse
M1B
P1A
P1B
P1C
P1D
P1E
PA
PB
PC
PD
PE
MB
Figure 3: Plan of the remains and of the tested elements (in black)
The losses caused by the collapse were the following: 4 pillars of the right part of the central
nave and one of the 4 pillars sustaining the main dome and the transept, the complete roof
and vault of the central nave, three quarter of the drum and dome with the lantern, the roof
and vault of the right part of the transept and part of the small domes of the right nave
(Figure 3).
Soon after the collapse the bishop, responsible for the Cathedral, clearly expressed in name
of the Catholic church the wish that St. Nicolò should be reconstructed as it was. For the
mayor and some of the citizens the reconstruction of the Cathedral could become a symbol
of a new life for Noto, the “baroque city” up to then partially abandoned with empty and
damaged buildings. Three choices were available for the Cathedral: 1) to leave it at the state
of ruin, avoiding a reconstruction which could attempt to the authenticity of the original
construction, 2) to reconstruct the collapsed parts with materials (concrete, steel) different
from the original ones, 3) to reconstruct with traditional materials respecting the pre-existing
volumes and shapes, but using a new technique of construction with the same type of
limestone and a new ready to mix mortar.
A team of experts together with the designers was studying the possible solutions, taking
into account the position of the city in an intense seismic area frequently hit by earthquakes.
The first one was discarded due to the cost of preserving the ruins safe from earthquakes
and also to the fact that the large void left in the centre of the city would have been an
invitation to continue its slow decay (Figure 4). The second solution was not convincing due
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to the highly non symmetric structure which would result with old and new elements of very
different stiffness. Finally the third solution was chosen abandoning the idea of a philological
reconstruction and choosing a new design for the rebuilt parts.
Figure 4: The ruins of the Cathedral seen from a higher part of the city
3. On-site investigation: Layout of the pillar and wall section and of the material
characteristics
A careful investigation was carried out by L. Binda and G. Baronio, consultants of the
designers on the walls, vaults, domes and on the materials (stones and mortars) used for the
construction of the Cathedral.
Nevertheless after the study of the collapse mechanism, carried out also on site during the
removal of the ruins [4], the attention of the consultants was focused on the careful study of
the peculiar features of the collapsed pillars, which were suspected of being the first to
collapse.
The removal by layers of the components of the collapsed pillars allowed to understand the
poor technique of construction used for them. Layers of large round river stones with thick
mortar joints, where the mortar appeared very weak and dusty, were found in the core of the
structure, surrounded by an external leaf made with regular blocks of more compact
limestone at the base of the pillars. Since only the base had remained after the collapse
(Figure 5) and the symmetric pillars were still covered by plaster, the hypothesis was made
at first that this limestone had been used for the external part of the whole pillars.
Figure 5: The remains of a collapsed pillar
This material, compact but not very strong, came from sedimentary carbonatic depositions
which can be found in the area and are still used as quarries for the building industry [5].
Inside the rubble filling also pieces of a material full of voids were found which was called
-3-
“local travertine”, a sort of tuff; this material is of the same nature as the limestone, but
deposited in the presence of turbulent waters and it is rich in voids of various shape and
dimension which previously contained organic parts later on dissolved.
The height of the blocks varied from 25 to 30 cm and the thickness, small compared to the
pillar dimensions, was ranging from 40 (stretcher) to 25 cm (header). The stones of the pillar
strips supporting the arches, vault and domes had no connection either to the internal
masonry or to the other parts of the external leaf (Figures 6 and 7).
Figure 6: Horizontal section of the pillar Figure 7: Reconstruction of a pillar section
directly surveyed
The inner part of the nave pillars represented 55 % of the entire section, while in the pillars
sustaining the dome it was 58 %. The courses of this rubble material were rather irregular
without any transversal connection or small stones to fill the voids and with thick mortar
joints. Nevertheless every two courses of the external leaf (about 50 cm) a course made with
small stones and mortar was inserted in order to obtain a certain horizontality (Figure 7).
Scaffolding holes were left everywhere, some crossing the whole section.
The mortar appeared to contain a high fraction of very small calcareous aggregates. Also the
bond between the mortar and the stones was very weak; in fact it was possible to remove
stones and pebbles from the interior of the pillars without any difficulty and with the stones
being completely clean.
This poor technique of construction and the use of the weak limestone (actually called “Noto
stone”) typical in the Noto region, was probably the cause of the damages to the pillars of
the Cathedral, even if a clear crack pattern was reported to have appeared only after the
1990 earthquake. The lateral loadbearing walls were built as first and similarly; nevertheless,
the internal part was made with smaller sharp stones alternated with a slightly stronger
mortar, in some way a better masonry. Some stones were sampled from pillars and walls
and mortar samples were taken from horizontal, vertical joints and from the interior of the
masonry (Figure 3). The samples were sent to the DIS Laboratory in Milan and tested in
order to find the material characteristics [2], [6].
The investigation has shown that the foundations of pillars and walls were sufficiently well
constructed: rubble walls but with enough load carrying capacity for the weight of the above
structures. The soil was a sort of natural compact silt and clay thick layer from where also
the aggregates of the mortars were taken.
On the materials sampled on site physical, chemical, petrographic-mineralogical and
mechanical tests were carried out in Milan at the DIS Laboratory. The aim was to
-4-
characterise the materials of a typical (CC’) transversal section (Figure 8) of the Cathedral
[6].
The chemical and mineralogical analyses were carried out following a procedure set up in [7]
on the mortars sampled from all the pillars and walls at different height. The mortars contain
a high percentage of CaCO3 showing that they are based on hydrated lime but with fine
aggregate size distribution. The soil was also examined and it appears of being composed
by more than the 87 % of calcium carbonate, by 8 % of different silicates and for the
remaining 5 % by alcali, allumine, iron, gypsum, etc. The grain size distribution of the soil
shows that it is composed for the 8 % by clay, the 72 % by silt and the 20 % by sand, a very
fine material.
Some compressive tests were carried out on cylindrical samples of the two stones,
limestone and travertine; their texture is shown in Figure 9a,b. The tests performed on the
limestone show that its strength when saturated at constant mass (11.56 N/mm2) drops
dramatically with respect to the strength measured when dried at constant mass
(17.98 N/mm2). The compressive strength of the travertine is very low and can vary from 4 to
6 or more N/mm2.
Figure 8 : Transversal Section CC’
Figure 9a,b: a) Calcarenite (Stone of Noto)
b) “local travertine”
In order to know the response of the two different stones to the elastic waves, the ultrasonic
velocity was determined by transmission on stone blocks. The two materials show very
different behaviour. In fact, in the case of the limestone (calcarenite) the values are almost
constant, between 2912 m/s and 3157 m/s with an average of 3068 m/s. The values of the
travertine are more scattered, with a measured velocity between 1325 m/s and 3548 m/s,
and an average of 1823 m/s. The scattering of the data is due to the presence of large voids,
randomly distributed in the material, and confirms the results of the mechanical tests.
Up to this point of the investigation, even if the weakness of the material used seemed to be
the cause of the high damage suffered from the earthquake, it did not clarify why the pillars
reached the collapse.
4. Survey of the remaining pillars of the central nave
The left pillars of central nave, still covered with a thick plaster, seemed to have suffered
minor damages; only small and diffused vertical cracks were present on the plaster.
Nevertheless the doubt that the damage could be deeper inside and perhaps even present
before the 1990 earthquake, suggested to carry out on these pillars a more accurate survey.
As the plaster made at the end of the works done in the fifties was partially removed, a
series of vertical large cracks was found, some of which filled with the gypsum mortar used
for the plaster (Figure 10a,b).
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Figure 10a,b: Large crack in a pillar and example of a crack filled with mortar
This finding gave the authors the first evidence that the damage was already present in the
fifties. The pre-existing crack pattern was clearly a damage from compressive stresses, a
long range damage dating probably even long time before the fifties. The lesson after the
collapse of the Civic Tower in Pavia in 1989 and the subsequent research taught the authors
that the damage would probably have progressed even without the earthquake, which only
accelerated the collapse. After the recognition of the damages, the removal of the plaster
from all the pillars was planned in order to survey the crack pattern.
Figure 11 shows a reconstruction of the crack pattern of the pillar before removing the
plaster. As it is possible to observe, the cracks are diffused and cover the whole surface,
with a concentration in the corners.
Figure 11: Prospect of pillar P1B and survey of the crack
A single flat-jack test was carried out on the pillar P1E in order to know the state of stress in
it simply due to the dead load of the pillar itself and a value of 0.85 N/mm2 was found at a
height of 3.00 m. Taking into account the missed weight of arches, vaults and dome in the
collapse, it is easy to make the hypothesis that the pillars must have been under a non
negligible state of stress.
Double flat-jack tests were also carried out on pillars P1E and P1A and on the external walls
of the Cathedral.
A double flat jack test was also carried out in the inner part of pillar P1A in order to check the
behaviour of its weakest part. Figure 12 shows the difference between the external leaf
(CNJ1D) and the core (CNJ2D) which had a much higher deformability and lower strength,
and probably had already settled long time ago, so that all the stresses were transferred to
the external leaves.
As a confirmation of the state of damage sonic pulse velocity tests were carried out on the
remaining pillars.
-6-
Stress [N/mm2]
2.0
σ
1.5
CNJ1d
Elastic modulus:1760 [N/mm2]
1.0
CNJ2d
Elastic modulus: 190 [N/mm2]
Local stress
0.5
0.0
εl
-6.0
εv
-4.0
-2.0
0.0
2.0
Strain [µm/mm]
4.0
6.0
Figure 12: Double flat jack carried out on the external and internal part of P1A
Measurements were taken at different heights (Figure 13). It was impossible to position
equal levels for all the pillars due to the presence of safety scaffolding. Nevertheless it was
clear that the material of the external blocks was changing from the base (limestone) to the
remaining part of the pillars (travertine).
The measurements were also carried out on some parts of the external walls as a
comparison. Figure 14 shows the average values over the measurements carried out in the
two orthogonal directions found for the left pillars and for the external pillar and wall called
M1B.
Low velocity values were systematically recorded in all the tested pillars of the Cathedral
from about 1.00-1.50 m on, that is above the limestone base.
The pillar P1B shows the lowest values of the sonic velocities recorded at each level
compared to the other P1i pillars. The pillar state is in fact also characterised by a very
serious damage, as described by the crack pattern of figure 7.
Figure 13: Geometry of the pillars P1E and Figure 14: Vertical distribution of the sonic
PE and localisation of the sonic
velocity measured on the pillars
tests
and the walls
The on site and laboratory research carried out by the authors concerned also the study,
(based on the results of surveys and tests), of the state of damage of materials and
structures and of their possibility of being reused. Furthermore the choice of the materials for
the reconstruction of the piers and of the missing parts and for repair and reinforcing was
-7-
taken into account together with the chemical, physical and mechanical compatibility of the
new materials with the existing ones.
Grouts were injected in some of the collapsed piers PC and PA (Figure 3) and on a
perimetral wall called MB to control the applicability of the technique and to chose an optimal
mix. Grout injections were used for strengthening and connecting the leaves of the pillars
and walls.
Injectability tests proposed in [8] were carried out in laboratory on materials sampled from
the internal part of the pillars and walls, and from the collapsed pillars of the Cathedral.
Grout injection was controlled directly on site as well [9].
Sonic tests were also carried out before and after injection. Generally an increase of the
sonic velocity is observed, as a consequence of the injection. Particularly for the pier PC
(Figure 15). It is also interesting to observe that in some cases the velocity values are similar
to the ones initially acquired, meaning that the grout was not uniformly diffused.
5. Design decisions
The accurate and detailed survey carried out by a multidisciplinary team was very helpful for
the designers who had to take many difficult decisions. The crack pattern survey revealed
large vertical cracks already present and filled with gypsum mortars in the fifties when the
timber roof of the Cathedral was replaced by a concrete roof. These damages indicate,
together with the laboratory results, that the material used for the construction was very
weak and damaged by long term effects; the collapse perhaps could have taken place in a
longer time without the earthquake.
Figure 15: Results of the sonic tests carried out on the pier PC at 25 cm height, before
and after the injection
Figure 16 shows as a confirmation the state of damage of one of the pillars as observed
after the complete removal of the plaster.
-8-
Figure 16: State of damage observed after the removal of the plaster
The left hand pillars could not be preserved due to the high state of damage caused by the
weak technique of construction and the weak materials; therefore it was decide to demolish
them and rebuild them, together with the collapsed ones using better materials and
technique of construction, i.e. using a new construction technique ready to mix hydraulic
mortars, limestone avoiding travertine and good connections between the external leaf of the
pillars and the core (Figure 17a,b).
a
b
Figure 17a,b: Layout of the new pillars
The substitution of the left pillars takes place in alternate order, demolishing one pillar at a
time and reconstructing it. Before this operation, the vaults of the left nave are supported by
a stiff steel structure (Figure 18).
Figure 18: Steel structure supporting the vaults
The dismantling of every single pillar is carried out in successive steps, demolishing stone by
stone every single course. The use of the local travertine is confirmed, as well as the serious
state of damage and the lack of connection between the external stone leaf and the core.
-9-
The stones showed passing through cracks or deep cracks; when lifted by the workers, the
blocks often broke, revealing the large internal voids (Figures 19, 20, 21).
Figure 19: Detail of fractures
Figure 20: Lack of connection between the
external leaf and the core
Figure 21: The use of “travertine” is confirmed
Furthermore the fractures in the external surface could be observed also in the internal
rubble, even if less readable because of the high inhomogeneity of the masonry. They in fact
can follow the boundary between the mortar and the pebbles, but also go through every
single stone.
The inside of the stones which are practically all broken or fissured is full of voids and very
weak. This explains why the pillar did not bear the state of stress for a long time. Creep
phenomena have certainly developed during the life of the pillars, lowering their strength.
The reconstruction of the Cathedral started in 2001, figure 22 shows a detail of the
reconstructed arches and vaults.
-10-
Figure 22: The reconstruction of one of the longitudinal and transversal arch
8 Conclusions
The decision taken by the community of Noto to reconstruct the partially collapsed Cathedral
seems to be justified for the following reasons:
- the preservation of the ruins, remaining after the collapse was considered to be too costly
to the community of Noto, also due to the difficulty of supporting them in a safe way with
added elements;
- the solution using other materials in the reconstruction would have created differences in
the stiffness of the structure which would have made the Cathedral vulnerable under future
earthquakes;
- the adopted solution of rebuilding was perhaps the most reasonable and also acceptable
as the exception which confirms the rule (of preservation).
The substitution of the remaining of the central nave was decided during the design of the
intervention, also following the frustrating tentative of repair by injection; nevertheless only
when the first remaining pillar was carefully dismantled it was possible to see the physical
composition of this wall and the real condition of damage. It was then clear that the pillars
could not be preserved.
Nevertheless the two pillars supporting the dome and built in the transept walls remained
untouched, so a memory of the old pillars and of their technique of construction was left for
the future. Furthermore the new pillars have been constructed with a different technique as it
can be seen in the previous sections.
The example of Noto with few others (e.g. the reconstruction of the Frauenkirche in
Dresden) remain as exception of the rule concerning the preservation of authenticity and
rather preservation of a memory. The case of Noto also showed that it is impossible to
rebuild “as it was” in totally different times from the original ones.
9. Acknowledgement
Authors wish to thank for their contribution Prof. G. Baronio for the work on material, M.
Antico, M. Cucchi, M. Iscandri C. Tedeschi and C. Tiraboschi.
-11-
10. References
1.
2.
3.
4.
5.
6.
7.
8.
9.
R. De Benedictis, S. Tringali, La Ricostruzione della Cattedrale di Noto, L.C.T. Edizioni
Ispica, 2000.
Binda, L., Baronio, G., Gavarini, C., De Benedictis, R. & Tringali, S., Investigation on
materials and structures for the reconstruction of the partially collapsed Cathedral of
Noto (Sicily), Proc. STREMAH 99, Dresden, Germany, pp. 323-332, 1999.
Tobriner S., Building the Cathedral of Noto; earthquakes reconstruction and building
practice in 18th Century Sicily, Construction Building Materials Journal, 2001, to appear.
De Benedictis, R., Tringali, S., Gavarini, C., Binda, L. & Baronio G., Methodology
applied to the removal of the ruins and to the survey of the remains after the collapse of
the Noto Cathedral in Sicily, Proc. STREMAH 99, Dresden, Germany, pp. 529-538,
1999.
Binda, L., Baronio, G., Tiraboschi, C. & Tedeschi, C., Experimental Research for the
Choice of Adequate Materials for the Reconstruction of the Cathedral of Noto,
Construction Building Materials Journal, 2001, to appear.
Baronio, G., Binda, L., Tedeschi, C. & Tiraboschi C., Characterization of the Materials
Used in the Construction of the Noto Cathedral, Construction Building Materials, 2001,
to appear.
Baronio, G. & Binda, L., Experimental approach to a procedure for the investigation of
historic mortars, Proc. 9th Int. Brick/Block Masonry Conf., Berlin, pp. 1397-1405, 1991.
Binda, L., Modena, C. & Baronio, G., Strengthening of masonries by injection technique,
Proc. 6th NaMC, Vol. I, Philadelphia, pp. 1-14, 1993.
Binda L., Colla C., Saisi A., Valle S., Application of Georadar to the Diagnosis of
Damaged Structures, 6° Int. Conf. Structural Studies, Repairs and Maintenance of
Historical Buildings, STREMAH 99, Dresden, Germany, pp. 13-22, 1999.
-12-
CONSERVATION OF MODERN ARCHITECTURE;
PARADOXOS, DILEMMAS AND APPROACH
Hubert-Jan Henket, Architect
1. Introduction
Since the main theme of this colloquium is “Authenticity and restoration of Monuments”, I
first like to talk about authenticity, then about restoration principles and about their relation
with monuments in the 20th Century.
A strange feeling invades you when revisiting a building or a spot once dear to you, in
search for the original experience you had. A spot where you played as a child, a building
where you fell in love, an environment you enjoyed long ago. The spot has changed, there
are different things and different people and you have changed yourself. The original
emotion has evaporated into thin air. Yet, we all have is the urge to try to keep what was
dear to us. Whether one likes it or not we are confronted with the one and only constant of
being: everything changes, everything flows, Panta Rei. In most civilisations the inevitability
of change is encapsulated in a durable philosophy which relates the acceptance of being to
eternity. Western civilisation however has directed its attention towards human control, to
progress, to the here and now. This is why the tension between continuity and change has
occupied the Western mind more than others, particularly since the Renaissance and the
Reformation. First this dialectic evolved in a relatively slow pace but ever since the
Enlightenment and the Industrial Revolution and particularly since the beginning of the 20th
Century the dynamics of change became extremely powerful and thus the collision with the
desire to conserve. Together with the increase in the dynamics of change, the want of
keeping and conserving in our society increased simultaneously.
It is interesting to note that this conservation drive in our western societies is almost purely
related to the authenticity of the physical and the visual, contrary to for example to East
Asian civilisations. Let me quote the Japanese Architect Kishu Kurokawa [1]: “The Japanese
regard the Ise Shrine as a work of traditional architecture with a history of 1300 years, and
Today as one of the world’s oldest wooden buildings, dating from the Nara Period (….)
The Ise Shrine has been rebuilt every twenty years from completely new materials, and
Today underwent major reconstruction in the Kamakura and Edo Periods, so that its scale,
proportions and façade are different from the original. In western culture, a work must exist
in its original form and material to be considered authentic; if an exact model of the original is
built using new materials, no matter how precise the replication may be it is regarded as a
copy. This represents the difference between the ways the West and Japan regard cultural
transmission. The West seeks to hand down the actual physical original, while Japan hands
down the ideas, aesthetic sensibility, spirit and technique that are behind the physical
creation, placing a greater importance on the invisible tradition and making every effort to
keep it alive”. He goes on to say: “This attitude of the Japanese help to explain why we have
been so quick to destroy parts of our physical historical legacy and replace them with new
things. Of course, there is a great need for the Japanese to reconsider this tendency, but on
the other hand the importance that Japanese culture places on the invisible tradition opens
up enormous possibilities for the transmission of traditional culture,” to contemporary needs.
At the same time we may notice that our West European approach has the advantage of
being careful with our physical heritage yet there is an increasing danger of unfitting
armchair conservation, particularly regarding 20th Century conditions. Let me be more
precise.
-1-
2. Authenticity
The Webster’s Dictionary defines authenticity as “the state of being genuine, stressing that
the thing considered is in agreement with fact” [2]. But which fact may I ask. Is it what the
original architect intended or is it what he designed, or is it what was built, or is fact what has
been converted between then and now. Besides how can I be “in agreement with fact”, as
Webster advises me, if and when the needs and the patterns of usage have all changed, the
building technology, the production technology and the use of materials have changed, as
well as the political and cultural context. And confronted with 20th Century architecture
matters get even more complex because modern buildings are intentionally designed with
transitoriness in mind.
What all this means is that when confronted with the conservation of a building or ensemble
we have to make choices, choices concerning the past and choices concerning today. And
no matter how genuinely, objectively or carefully we analyse and determinate that past, it will
remain a subjective choice all together. Every period has its own specific realism which
Colours the way one looks at the present and thus at the past. I like to give you a beautiful
example of how one’s outlook can colour the way one looks at the past. It was in 1938 that
the master forger Han van Meegeren made his most famous painting “The Emmaus
travellers”. After the painting was so called “discovered” in an old French castle, the
complete Dutch art historical and museum establishment got exited about the discovery of
the Century. This was by far the best painting the 17th Century Dutch Master Johannes
Vermeer had ever painted. So the Dutch state for the Rijksmuseum in Amsterdam and the
private museum
Boymans van Beuningen in Rotterdam both assisted by the cream of art historical Academia
competed in extravagant bidding. Private money won the battle and so it was that Boymans
van Beuningen organised a celebratory exhibition in honour of Vermeer and his “Emmaus
Traveller”. Well the art critics of the time heralded the beauty and the authenticity of
Vermeers painting in their newspapers and scientific magazines. Look at the composition,
look at the treatment of light, look at the hands of Jesus they wrote, this is authentic Vermeer
at his best. Several years later however, directly after the end of the war van Meegeren was
convicted of collaboration with the Germans, because he had sold 17th Century Dutch
Masters to the enemy. This made him furious. Much could be said about him but no way was
he a traitor. To counter this accusation he demonstrated in court that he was not a
collaborator but a forger, and suddenly “the Emmaus Travellers” was not a Vermeer but a
Van Meegeren painting. Of course the interesting question is how come that all these
excellent professors and critics were so convinced in 1939 to be confronted with an
authentic Vermeer painting. When we look at the painting today we cannot understand why
they all made this mistake. Well simply, because van Meegeren was a real master forger.
He painted the Emmaus travellers the way people at the end of the nineteen thirties looked
at the world, at art and at the past. What they saw as their nineteen thirties interpretation of
17th Century Dutch painting. And this teaches us that what we see is our interpretation of
what there is, it is subjective per definition. However this shouldn’t scare us.
We have to make choices today and provided we make these choices responsibly,
consciously and with sound motivation this is the best we can do. Designing and building is
serving life as it is lived, it is about vitality and so is conservation. As John Allan in “Back
from Utopia” rightly said: “The acceptance of change is the essential precondition of real
conservation” [3]. It needs a pragmatic rather than a dogmatic approach, an approach that is
flexible defending on the characteristics of the object concerned, its canonical status, and
it’s possibilities for re-use.
3. Restoration
Restoration principles as they are accepted today as represented by the Venice Charter are
from 19th Century origin. The aim is “to conserve through the most discreet repair work every
-2-
aspect of the long accumulated history of a building, refraining in the process from any work
which is not based on evidence …” [4]. But both 20th Century legislation and 20th Century
buildings don’t quite fit this approach. As a consequence of the rapid changes in
requirements, conditions and context in 20th Century societies, the essence of modern
architecture is (as I mentioned before) its transitoriness both conceptually, functionally,
technically and aesthetically.
And thus the essence of it’s preservation should be transitoriness as well. As you will
understand this involves some far reaching consequences. Let me mention a few:
- Current functional requirements such as new labour condition legislation or current
technical requirements such as safety health or environmental legislation have the
peculiarity of always asking for more rather than less, being a consequence of our Western
dedication to progress. This means more space is required then before, more layers, more
material, more energy. As regards pre 20th Century buildings designed with eternity or at
least a very long life in mind, there is some room to manoeuvre. But since 20th Century
buildings were originally designed with transitoriness in mind, stringent economic
limitations were attached, leaving very little room for manoeuvre today. Space is limited
and constructions are thin and fragile. And therefore when conserving 20th Century
buildings it is not enough to repair discretely. Substantial interventions are required as well
to bring them to standard.
- There is also the phenomenon of the renewal of materials and particularly products and
services which are not produced (non existent), any longer. Think of plastics, types of
glass, laminates, light fittings, central heating equipment, etc. It gets even more intriguing
thinking about changing concepts of climatic control, due to new environmental and
comfort requirements. If you continue this line of thought and trend one should wonder
what will be left of the original building both in concept and materialisation in say two or
three generations. If anything, this stresses the importance of documentation of both the
existing and the intervention in any conservation activity. Besides it requires a much more
structured and integrated debate by the official institutions on how to preserve the past for
future generations given the current circumstances.
4. Case 1: Sanatorium Zonnestraal at Hilversum, NL
I like to conclude with some cases to demonstrate the points I made before.
First I will show Sanatorium Zonnestraal at Hilversum (The Netherlands) a 20th Century
candidate for the World Heritage List. In the wooded countryside approx. 35 km from
Amsterdam an estate was bought in the 1920’s by the first Dutch trade Union, the diamond
workers Union, for their members who suffered from Tuberculoses due to inhaling diamond
dust. The young Dutch architect Jan Duiker was commissioned to make a design for the
sanatorium consisting of two pavilions, a main building and some other structures. Duiker, a
true believer in modernity, wanted to act as efficiently as possible both intellectually,
functionally as well as technically in all his design decisions, in order to have a maximum of
resources available for the elevation of mankind. So he designed every building and even
every space in such a way that it would fit the particular functional requirements like a glove.
In the same line of thought it only made sense to him to design the materialisation of that
building with a technical durability that would coincide with its functional life expectancy. And
because as modernist he believed in scientific progress, tuberculoses would cease to exist
within thirty years, due to the invention of medicines. And so he designed Zonnestraal with a
life expectancy of approx. thirty years. In other words he purposefully designed throwaway
buildings.
In the fifties his prophecy turned out to be correct and the need for the sanatorium
disappeared. Its function was converted to a hospital and due to the increase of hospital
regulations, numerous conversions, adoptions, and extensions were realised. In the early
nineties the inefficiency of the complex reached such a level that the complex was vacated
and the hospital moved to another location. In the meantime the international canonical
-3-
status of its architecture was firmly established. And so we were faced with the paradox of
preserving throwaway buildings for eternity.
Since 1982 my colleague Wessel de Jonge and I have been involved in trying to find new
occupants for the buildings. This wasn’t easy because its tailor made minimalism, and
transitoriness, are the two conceptual pillars of its architectural quality and canonical status.
The problems were many. First it was hard to find a new main function that would somehow
fit Many times it proved too difficult to get a match between functional and technical demand,
preservation ideals, and financial consequences (not withstanding generous state
assistance).
Since 1996 we are working together with the original user of the complex who is trying to
establish a curative and preventive health centre. This seems a logical function for the
sanatorium but the initiative encounters a wide scale of difficulties. I am glad to inform you
that the restoration of the main building will be finished in a few months time, but don’t ask
me how much energy this has cost from all concerned. Hopefully one of the pavilions will be
ready in three years.
Functionally tailor made buildings, like the pavilions create some very basic problems. Our
current comfort standard doesn’t agree any longer with rooms of 3 x 3 meter without a
private bathroom. Even when we were negotiating with the Federation of Trade Unions, as
possible new users of the complex, they refused to accept rooms without private bathrooms
for a short three-day stay of their members. So any re-use of the pavilions meant a
completely different room arrangement and the abolishment of the communal bathrooms.
Yet it is precisely the functional arrangement of these spaces, which was the reason for its
original form which we adore so much today.
Let me also tell you something about the windows of the main building. Although we got a
waver for energy saving requirements to avoid double glazing, none of the candidate users
and the final user were prepared to except single glazing due downdraft in combination with
limited space available. So for several rooms double-glazing was unavoidable. A serious
problem, because the original window frames of 35 mm steel sections are one of the main
characterises of the unbelievable lightness of the original architecture. And as the architect
Aldo van Eyck once remarked: “Thickening the window frames of Zonnestraal, would be the
same as adding 1 mm to the lines in a Mondrian painting: If you would do that it wouldn’t be
a Mondrian any longer but just a painting.” In the end we managed to solve the problem
within the dimensions of the frame with a 4-4-5- mm solution.
In Western Europe no drawn glass is produced any longer as was originally used, but only
float glass. And float glass is visually killing in pre war buildings due to its flatness and its
darker appearance. On top of that the elimination of silicates in glass production in order to
arrive at clear glass, which traditionally was done with a cadmium solution, is prohibited in
Europe for environmental reasons since twenty years. After very extensive research drawn
glass with vertical stripes and cleared of silicates was found in Lithowenia. The inner glass of
the double-glazing system has to be float to avoid a moiré effect. The clearest float glass
available is to be found in the USA because of less stricter environmental legislation over
there. There are many more interesting details to be told, but due to the limitation of this
presentation I should like to confine myself to mention that our goal or stay as close as
possible to the original is extremely complicated and expensive both in respect to investment
and to exploitation due to heavy maintenance in the future. And notwithstanding all that
effort it will not deliver the comfort a user today requires. This is why this type of approach
can only be confined to the top icons of the 20th Century.
5. Case 2: School of Art at Arnhem, NL
The second case is the school of Art in Arnhem designed by Gerrit Rietveld in 1958.
Because of its age being under the fifty year limit it has no official state protection and
architectural historians consider it of medium importance in Rietveld’s oeuvre. Yet the school
of Art was very keen to renovate the building adhering to its original concept and visual
-4-
characteristics as much as possible. In the early sixties a single glazed curtain wall
construction made sense because it was one of the cheapest elevation solutions at hand
and it was pré oil crisis so heating costs were limited anyway. However the students and
teachers started to hate the bad comfort provided by this solution, working in a hot house in
summer and a cold box in winter. Everything was tried to solve this, nothing worked. So in
the end a major renovation was the only answer. Rietveld, like Duiker a modernist, designed
a minimalist building as well. So to adapt the building to the requirements of today was a
struggle against dimensions. If we would keep the single glazed solution to maintain the
visual fragility from the outside it would require an increase of service ducts to such an
extend, that it would ruin the original spacious quality on the inside. If we would want to solve
the problem only in the curtain wall, it would have required such heavy thermal protection
precautions that the building would loose its visual quality altogether. So we solved the
problem through a combination of the two. We calculated the maximum of services possible
without visual disturbance in the void between the structural ceiling and the false ceiling, and
a maximum of thermal protection in the curtain wall with a minimum of visual disturbance.
This in the end resulted in a double-glazing construction in a newly designed window frame.
As a demonstration of new interventions I like to show the glass bridge, we designed to
connect Rietveld’s building to an adjacent building. Recently we started with the construction
of an extension to Rietveld building for the new faculty theatre and dance which in volume
will be bigger than the original building. In order not to disturb the Rietveld building in its
solitaire setting, we designed the new extension as an underground building. It will be
finished in 1,5 year from now.
6. Case 3: Kunsthal at Rotterdam, NL
I like to conclude by showing the Kunsthal in Rotterdam designed by Rem Koolhaas in 1988
as a demonstration to a much broader problem. It will take another 36 years before this
building will get a protected status. However, changes are being prepared to make the
building functionally more appropriate which go against the original conceptual idea. There
are many more buildings although with less architectural status but with high quality which
are intervened with now. What will be left of the authenticity by the time they will be eligible
for official protection. And even if they would be protected today what will be left of their
authenticity anyway. I would like to put to you the following argument:
Our Western societies are characterised by the Modernist ideal of progress. One of the
implications of this is that we increase the requirements for buildings to an ever higher level.
Equally this has meant that 20th Century buildings are characterised by transitoriness. For
the world of conservation this means that the 19th Century principles of authenticity of
concept form and of materialisation based on long life and durability don’t fit any longer. If we
continue to apply these 19th Century principles to 20th Century architecture we will be left
with total fake. In the end this might lead to exiting theme parks but not to what was the
intention in the first place. So I ask you, doesn’t this require a revised vision of what we will
leave behind as the cultural heritage of our time and particularly how best we can do this? It
requires a completely different attitude, vision and approach.
7. References
1. Kishu Kurokawa in Back from Utopia, edited by Hubert-Jan Henket and Hilde Heynen,
Rotterdam 010, 2002, page 256
2. Webster’s New World Dictionary, David B. Guralnik, New York, 1984
3. John Allan in Back from Utopia, edited by Hubert-Jan Henket and Hilde Heynen,
Rotterdam 010, 2002, page 21
4. www.personal.inet.fi/koti/marc99/dbernstein.html page 1
-5-
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
-6-
Figure 8
Figure 7
Figure 9
Figure 10
Figure 12
Figure 11
-7-
Figure 13
Figure 14
Figure 15
-8-
WTA-colloquium:
WTA-Kolloquium:
Authenticity in the restoration of monuments
Authentizität in der Denkmalpflege
14th March 2003 – 14. März 2003 Leuven Belgium/ Belgien
Addresses, Phone, e-mail etc. of the speakers and the organisation
Adressen, Telephon, Email usw. der Referenten und die Organisation
Prof. Dr. Ir-arch. Koen Van Balen
Getty Conservation Scholar
Getty Conservation Institute
1200 Center Drive, Suite 700
CA-90049 Los Angeles
USA
Tel.
+1 310 440-7531
Fax
+1 310 440 7702
[email protected]
Departement Burgerlijke Bouwkunde
Attn. Mevr. K. Loonbeek
Kasteelpark Arenberg 40
B-3001 Heverlee
Tel.
+32 16 321654
Fax
+32 16 321976
[email protected]
Prof. Luigia Binda
DIS Dip. Di Ingegneria Strutturale
Politecnico di Milano
Piazza Leonardo Da Vinci 32
I-20133 Milano
Italy
Tel.
+39 02 23994318/4208
Fax
+39 02 23994220
[email protected]
Ing. Bert van Bommel
Atelier Rijksbouwmeester
Noordeinde 64
NL-2514 GK Den Haag
Tel.
+31 (0) 70 3420121
Fax
+31 (0) 703420025
[email protected]
Prof. Ir. Jo Coenen
Atelier Rijksbouwmeester
Noordeinde 64
NL-2514 GK Den Haag
Tel.
+31 (0) 70 3420034
Fax
+31 (0) 703420025
[email protected]
Prof. Dr. Wim Denslagen
Rijksdienst voor de Monumentenzorg
Postbus 1001
NL-3700 BA Zeist
Tel.
+31 (0) 30 6983366
[email protected]
Diplom.-Rest. Stefan Grell
Caro Restaurierung und Technologie GmbH
Schönhauser Allee 51
D-10457 Berlin
Tel.: +49 (0) 30 4403460
Fax.: +49 (0) 30 44034610
[email protected]
Prof. Ir. Hubert Jan Henket
Hubert-Jan Henket architecten b.v.
Postbus 2126
NL-5260 CC Vught
Tel.
+31 (0) 411 601618
Fax
+31 (0) 411 601887
[email protected]
Bob van Reeth
Vlaams Bouwmeester
Graaf de Ferrarisgebouw
Koning Albert II-laan 20 bus 9
B-1000 Brussel
Tel.
+32 (0) 2 553 74 00
Fax
+32 (0) 2 553 75 00
[email protected]
Organisation/Organisation
Ir. R. van Hees p/a TNO - Bouw
Schoemakerstraat 97
Gebouw O
Postbus 49
NL - 2600 AA Delft
Tel.: + 31 (0)15 276 31 64
Fax: + 31 (0)15 276 30 17
[email protected]
Ton Bunnik
Van Pelt reiniging bv
Strickledeweg 31b
NL-3125 AT Schiedam
Tel.: +31 (0) 10 4620388
Fax.: +31 (0) 10 4154868
[email protected]
K.U. Leuven Belgium/ Belgien
Partner in Leuven / Ansprechspartner vor Ort
Prof.Dr.Ir.Dionys Van Gemert
Dept.Burgerlijke Bouwkunde
Laboratorium Reyntjens
Kasteelpark Arenberg 40
B - 3001 Heverlee
Tel.: + 32 16 32 16 71
Fax: + 32 16 32 19 76
[email protected]
WTA
Sekretariat: Frau Schneider
Tel:
+49 (0)89 578 69727
Fax: +49 (0) 89 578 69729
E-Mail: [email protected]
Location of the Colloquium / Ort des Kolloquiums
Promotiezaal
Katholieke Universiteit Leuven
Naamsestraat 22
B-3000 Leuven
K.U. Leuven Belgium/ Belgien
Partner in Leuven / Ansprechspartner vor Ort
Krisitne Loonbeek
Dept. Burgerlijke Bouwkunde
Laboratorium Reyntjens
Kasteelpark Arenberg 40
B - 3001 Heverlee
Tel.: + 32 16 32 16 54
Fax: + 32 16 32 19 76
[email protected]
De WTA stelt zich voor
Wetenschappelijk – Technische Groep voor Aanbevelingen inzake
Bouwrenovatie en Monumentenzorg.
Er bestaat in binnen - en buitenland, versnipperd over vele bedrijven en instellingen,
researchafdelingen en adviesorganen, een uitgebreid aanbod van kennis op het
gebied van bouwrenovatie en – instandhouding. Van die kennis zou de
bouwrenovatie markt en daarmee ook de zorg voor de monumenten meer kunnen
profiteren dan nu het geval is, en dat eens te meer daar het zwaartepunt van die zorg
geleidelijk verschuift van de traditionele restauratie naar renovatie en onderhoud en
bovendien
de
“jonge“
monumenten
met
een
geheel
eigen
conserveringsproblematiek, in de zorg worden betrokken.
Probleem is echter, dat dit grote kennisaanbod niet zo gemakkelijk is te overzien en
zich bovendien steeds aanpast. Het adagium “ bouwen is traditie “ gaat steeds
minder vaak op, en dat geldt evenzeer voor renovatie - en onderhoudstechnieken.
Kwaliteit, bruikbaarheid en actualiteit van kennis staan daarbij voorop. De
Nederlands -Vlaamse afdeling van de WTA kan daarbij een belangrijke rol spelen.
De WTA beijvert zich voor onderzoek en de praktische toepassing daarvan op het
gebied van onderhoud aan gebouwen en monumentenzorg.
Daartoe worden bijeenkomsten van wetenschapsmensen en praktijkdeskundigen
georganiseerd, waar een specifiek probleem inzake onderhoud van gebouwen en
duurzaamheid van gebruikte bouwmaterialen en methoden zeer intensief wordt
onderzocht en aan de bestaande ervaring met studiewerkgroepen op onder meer het
terrein van
HOUTBESCHERMING,
OPPERVLAKTETECHNOLOGIE,
METSELWERK,
NATUURSTEEN
en
STATISCHE
/DYNAMISCHE
BELASTINGEN
VAN
CONSTRUCTIES. Deze werkgroepen hebben tot doel kennis en ervaringen uit te
wisselen.
Resultaten
worden
vertaald
in
een
richtlijn
voor
werkwijzen
en
behandelingsmethoden.
Gezien de kwaliteit en de heterogene samenstelling van de werkgroepen, kunnen die
richtlijnen, zogenaamde Merkblätter, beschouwd worden als objectief en
normstellend
Advisering inzake restauratie en onderhoud. Zij worden in brede kring verspreid door
middel van publicaties in de vakpers en in het WTA-tijdschrift “Restoration of
buildings and monuments” gepubliceerd dat aan alle leden 6x per jaar wordt
toegestuurd.
Leden van de WTA kunnen aldus, door een actieve vertegenwoordiging in
werkgroepen bijdragen aan de totstandkoming van dergelijke normstellende
advisering.
In beginsel staat het lidmaatschap open voor allen die vanuit hun functie of
belangstalling bij de bouw, restauratie en het onderhoud van gebouwen betrokken
zijn. Werkgroepen worden samengesteld op basis van deskundigheid en ervaring
van de participanten. Deelname is altijd vakinhoudelijk. Leden hebben het recht
voorstellen te doen voor de op - en inrichting van nieuwe werkgroepen en gebruik te
maken van door de WTA geleverde faciliteiten zoals een vakbibliotheek en enig
administratieve ondersteuning.
Het betreft daarbij niet alleen advisering, maar ook het harmoniseren van de
verschillende internationale technische regelgevingen. Voor een goed functioneren
van zowel de opbouw uitmaken. Hiertoe biedt de Nederlandse tak van de WTA een
uitstekende mogelijkheid.
Wanneer u belangstelling heeft voor de WTA of één van de hiervoor genoemde
vakgebieden of werkgroepen kunt u met de WTA Nederland -Vlaanderen in contact
treedt.
Kosten van het lidmaatschap bedragen: € 170, -per jaar per persoon,
Eenmalig inschrijfgeld van:
€ 25, -Een ondersteunend lidmaatschap voor bedrijven en instellingen kost minimaal
€ 170, -- tot € 610, -- per jaar. , Al naar gelang het aantal werknemers.
Eenmalig inschrijfgeld vanaf:
€ 25, -- tot € 150, -WTA Nederland - Vlaanderen
Correspondentieadres Nederland
Secretariaat WTA
P/a Prins Bernhardlaan 26
5684 CE Best
Tel. : 0499 – 375289 / 396062
Fax : 0499 – 375006
e-mail : [email protected]
Internet : www.wta-nl-vl.org
Correspondentieadres België
Mevr. Kristine Loonbeek
P/a Katholieke Universiteit Leuven
Departement Burgerlijke Bouwkunde
Laboratorium REYNTJENS
Kasteelpark Arenberg 40
3001 Heverlee
Tel. : 016 32 16 54
Fax : 016 32 19 76
e-mail : [email protected]
COLOFON
Concept en eindredactie
WTA Nederland - Vlaanderen
© WTA en Auteurs 2003.
Niets uit deze uitgave mag worden verveelvoudigd en/of openbaar gemaakt zonder
voorafgaande schriftelijke toestemming van de uitgever.
Voorblad: Beeldmateriaal ter beschikking gesteld door WTA
Uitgever
WTA NEDERLAND - VLAANDEREN
Correspondentieadres Nederland
Secretaris WTA NL - VL.
Prins Bernhardlaan 26
5684 CE Best
Tel. : 0499 - 396062/ 37 52 89
Fax : 0499 - 37 50 06
E-mail : [email protected]
Correspondentieadres België
Mevr. Kristine Loonbeek
Katholieke Universiteit Leuven
Departement Burgerlijke Bouwkunde
Laboratorium Reyntjens
Kasteelpark Arenberg 40
Tel. : 016 32 16 54
Fax : 016 32 19 76
E-mail: [email protected]
© 2003 ISBN 90-76132-13-5
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