Rehabilitation of a stone house in Saint-Cast

Ca s e S tu d y : Re h a b i l i ta ti o n o f a s to n e h o u s e i n S a i n t-Ca s t
We b s i te : h ttp ://www.co n s tr u cti o n 2 1 .o r g /
Rehabilitation of a stone house in Saint-Cast
PUBLISH BY LEVENOK | 17 JUNE 16
Pro ject type : Extensio n + refurbishment
Building Type : Iso lated o r semi-detached
ho use
Co nstructio n Year : 19 20
Climate zo ne : [Cfb] Marine Mild Winter,
warm summer, no dry seaso n.
Net Flo o r Area : 18 8 m 2
Co nstructio n/refurbishment co st : 50 0
000 €
Number o f Dwelling : 1 Dwelling
Co st/m2 : 2 6 6 0 €/m 2
Co st/Dwelling : 50 0 0 0 0 €/Dwelling
Rue du clo s co tillo n , 2238 0 Saint-Cast-leGuildo t, France
// Description
This small sto ne ho use in Saint-Cast, built in 19 20 by the grandparents o f the Owner had never been reno vated. The Owner
wanted to o ffer his mo ther to return to this ho lidays place in co mfo rt.
Originally, o nly a reno vatio n o f the existing building was talked abo ut and the request extended to creating a veranda o pening
o nto the garden.
The build quality o f the o riginal ho use and its ideal o rientatio n (so uth) pushed us to pro po se a real investment fo r a
sustainable ho me, largely bio -based and eco no mical.
To day he even use the ho use fo r his o wn vacatio ns.
Se e m o re de t ails abo ut t his pro je ct :
http://www.carabo x.co m/architecture/rehab_stCast.php (...)
Dat a re liabilit y :
Self-declared
// Stakeholders
Contractor representative
Name : Michel Leveno k
agence@carabo x.co m
Website : http://www.carabo x.co m/
Designer
Name : Carabo x SARL
Virginie Leveno k ; agence@carabo x.co m
Website : http://www.carabo x.co m/
Company
Name : Chassé
Daniel Chassé
Website : http://www.maiso ns-bo is-chasse.co m/
Actio n : frame / walls / insulatio n / flo o ring
Company
Name : FORPAC ETAO
Yo ann Taraud
Website : http://www.fo rpac.fr/
Actio n : drilling / geo thermal
Company
Name : To utain
Mo nsieur To utain Yvo n à Plébo ulle
Actio n : Maso nry / sto ne maso n / sto ne facing
Company
Name : Lemarchand
Jean-Michel Brigno n
Actio n : slab / structure
Manufacturer
Name : Acthys
Stephan Lerner
Website : http://www.acthys-ventilatio n.fr/
Actio n : natural humidity co ntro lled ventilatio n
Co nt ract ing m e t ho d :
General Co ntracto r
Owne r appro ach o f sust ainabilit y : Enviro nmental co nsideratio ns were no t part o f the requests o f the client, but mo st o f
o ur pro po sals have fo und a listening ear.
Thus it has been appro ved to build wo o d, iso lating wo o l and wo o d fiber, to reco ver rainwater fo r watering and spreading to
tho se
were no t reco verable, revegetated the inaccessible part o f the terrace, installing a geo thermal system, etc.
The extensio n was o riginally designed as a separate space heating was passively pro vided by its so uth facing windo ws that
are
pro tected fro m the summer sun by the cap created by the ro o f deck.
The pro ject o wner has cho sen that this space is the extensio n witho ut thresho ld o f the o riginal ho use. If necessary, this space
can be heated o r co o led
the same flo o r heating system to geo thermal was cho sen fo r the rehabilitatio n o f the o riginal ho use.
Fo r the sake o f efficiency and simplificatio n, this ho use is a seco nd ho me, the idea o f
a so lar ho t water system was
abando ned, whereas the ro o f pitch was no t ideal and uno ccupied perio ds were likely to cause o verheating.
Fo r the same reaso ns, the humidity sensitive ventilatio n is but natural. We relied o n a clever use o f the premises, the windo ws
are o pen allo wing
natural flo w o f air bearing sea impairment o f natural ventilatio n in ho t weather.
Archit e ct ural de script io n : The o riginal request o f the o wner was, besides the reno vatio n o f the ho use, adding a po rch to
the kitchen to enjo y the garden level ...
The idea o f veranda, we kept the essence: the wide o pening to the garden, as in the living ro o m created o n the gro und flo o r o n
the terrace accessible fro m the great ro o m o n the 1st flo o r which o ffers the lo o k no w turn to the sea.
Based o n a go lden rectangle, which also determines the po sitio n o f the do o rs, the space do ubles the surface o f the gro und
flo o r and o ffers a place o f receipt, while the o riginal ho use o nly co nceded small narro w ro o ms.
View o f the exterio r, the general line o f the extensio n is a reflectio n o f enviro nmental cho ices.
If yo u had t o do it again? : Because it was initially decided to keep the o riginal walls and the staircase, the plan o f the
ho use was no t upset. The co nstructio n system partitio ns finally allo wed their remo val and the client ultimately cho se to
replace the stairs.
If it again, we certainly agencerio ns spaces differently in the o riginal ho use.
Building use rs o pinio n :
Very go o d feedback o f o ccupants who asked us fo r ano ther realizatio n.
// Energy
Energy consumption
Prim ary e ne rgy ne e d :
11,46 kWh EP/m 2 /an
Prim ary e ne rgy ne e d f o r st andard building : 48 ,30 kWh EP/m 2 /an
Calculat io n m e t ho d : RT 20 12
CEEB : 0 ,0 0 kWh PE / €
Mo re inf o rm at io n : Because it is a seco nd ho me, the real co nsumptio n is no t representative. Fo r example, in 20 15: the
o ccupancy rate is 2 mo nths o f summer.
Init ial co nsum pt io n :
50 5,0 0 kWh EP/m 2 /an
Envelope performance
Enve lo pe U-Value : 0 ,33 W.m -2 .K-1
Mo re inf o rm at io n : In the rehabilitated part, there was no questio n o f lo sing the cachet o f the sto ne o f Saint Cast, wall
insulatio n has been carried o ut fro m the inside.The repair o f the co ver is pro vided, the ro o f insulatio n was perfo rmed
sarking, resulting fro m the fact raiser flues.In extensio n, the structure is wo o d and insulatio n level lo w co nsumptio n building
partly wedge between the structural elements.Co verage is largely a terrace available, the small inaccessible part is
vegetated.Laundry and unheated equipment ro o m were iso lated fro m the o utside.
Building Co m pact ne ss Co e f f icie nt : 0 ,6 2
// Renewables & systems
Systems
He at ing syst e m :
Geo thermal heat pump
Lo w temperature flo o r heating
Wo o d bo iler
Ho t wat e r syst e m :
Heat pump
Co o ling syst e m :
Geo thermal heat pump
Ve nt ilat io n syst e m :
Natural ventilatio n
Re ne wable syst e m s :
Wo o d bo iler
Heat Pump o n geo thermal pro bes
Heating, co o ling and ho t water are generated by a geo thermal system o n heated flo o rs.The idea o f a so lar ho t water system
was discussed but abando ned, whereas the ro o f pitch was no t ideal and that, in respect o f a seco ndary residence, vacancy
perio ds were likely to 'cause o verheating pro blems.
Natural ventilatio n and humidity co ntro lled (see do cument attached) with air fed thro ugh walls and extractio ns thro ugh the
attic. To o verco me a po ssible po wer failure summer ventilatio n, po wer lines were drawn at each air o utlet.
Geo thermal heat pumpPo wer = 8 6 40 W
COP = 4.59
So lut io ns e nhancing nat ure f re e gains : So uth o rientatio n o f the extensio n and main parts with a cap fo r summer
co mfo rt.
Smart Building
BMS :
Po wer switch fo r each main ro o m.
// Environment
Life Cycle Analysis
Eco -de sign m at e rial : - wo o den structure
- wo o d wo o l
- Wo o d fiber
- Birch parquet / special o ak flo o r heating
- wo o den windo w
Water, health & comfort
RECOVERY OF RAIN WATER
The slo ping ro o f water reco very system used fo r watering the garden, rainwater fro m the terrace (no t reco verable under the
regulatio n) are rejected applicatio n.
Theo retical capacity: 27m3
WATER SUPPLY SYSTEM
The supply system was taken to its o rigin in ro ads and past Reticulated Po lyethylene until meter and co pper in ho using.
Indo o r Air qualit y : The ho use is lo cated in a sparsely develo ped area, the quality o f indo o r air is acquired by natural
ventilatio n and the use o f no n-to xic materials.
He alt h & co m f o rt : To limit the risks o f so lvents, paints and o ils used were VOC and fo rmaldehyde-free OSB, vitrified
flo o ring in the wo rksho p.
Aco ust ic co m f o rt : The ho use is lo cated in a very little urbanized area, aco ustic co mfo rt lies to hear o utside so unds
natural, so we intentio nally selected windo ws witho ut enhanced so und insulatio n.
Daylight f act o r : 2,6 po ur le séjo ur et 8 ,14 po ur l'extensio n
// Products
Geothermal heat pump
Pro duce r : FORPAC ETAO
Co nt act : Yo ann Taraud
We bsit e : http://www.fo rpac.fr/
Pro duct cat e go ry: HVAC, électricité / heating, ho t water
De script io n :
heat pump co llect calo ries in depth in an area where the so il temperature varies little and
returning warmth o r co o lness by underflo o r heating (o r co o ling).
Co m m e nt s :
The cho ice o f a geo thermal system was actually an enviro nmental co mmitment by the pro ject
o wner because the return o n investment fo r ho using in Britanny mainly inhabited was no t granted. The idea do es no t suffer
fro m tariff increases fo r gas and tho se little electricity was to seduce the client.
http://www.co nstructio n21.o rg/data/so urces/users/7
Natural ventilation hygroadjustable
Pro duce r : Acthys
Co nt act : Stephan Lerner
We bsit e : http://www.acthys-ventilatio n.fr/
Pro duct cat e go ry: HVAC, électricité / ventilatio n, co o ling
De script io n :
By a membrane system sensitive to ambient humidity, ventilatio n o pens o r clo ses. The draw is
then made by depressio n, naturally.The system o perates less in summer (especially if the
o utside temperature exceeds the indo o r temperature), an electrical assistance may be added
later.
Co m m e nt s :
This system wo uld avo id the installatio n o f a co mplex system o f Mechanical ventilatio n and needs no electricity.
http://www.co nstructio n21.o rg/data/so urces/users/7
Wood wool insulation
Pro duce r : Actis
Co nt act : http://www.actis-iso latio n.co m/co ntacts.php?p=1&l=1&rub=6 &vert=1
We bsit e : http://www.actis-iso latio n.co m
Pro duct cat e go ry: Finishing wo rk / Partitio ns, insulatio n
De script io n :
Unlike ro ck wo o l, wo o d wo o l co mes fro m renewable material and do es no t require as many
energetic expenditure fo r the develo pment o f the material. This is an insulato r which has
advantages in summer co mfo rt and management o f hygro thermal co mfo rt.
Co m m e nt s :
Actis certainly wo uld no t have been my cho ice (o ther co mpanies are much mo re co mmitted to the enviro nment), but this
cho ice was delegated to the carpentry business
http://www.co nstructio n21.o rg/data/so urces/users/7
Wood structure
Pro duce r : CHASSÉ
Co nt act : Chassé Daniel
We bsit e : http://www.maiso ns-bo is-chasse.co m/
Pro duct cat e go ry: Structural wo rk / Structure - Maso nry - Facade
De script io n :
Renewable materials, to limit the thickness o f the walls, the structure invo lved in the insulatio n,
a wo o d structure is naturally stable fire, did no t require co mplicated apparatus fo r its
implementatio n and will require little energy to its deco nstructio n.
Co m m e nt s :
The client had no a prio ri, it was easily co nquered.
Sarking
Pro duce r : STEICO
Co nt act : http://www.steico .co m/fr/service/demande-co ntact/
We bsit e : http://www.steico .co m/fr/
Pro duct cat e go ry: Finishing wo rk / Partitio ns, insulatio n
De script io n :
The sarking o r insulating a ro o f fro m o utside fo r enjo ying the re-ro o fing to iso late o r impro ve
insulatio n, while maintaining the internal vo lume.Here, we cho se wo o d fiber fo r its stiffness and
its simplicity o f implementatio n.
Co m m e nt s :
The pro ject o wner has accepted witho ut questio n all o ur insulatio n pro po sitio ns ... but we were no t able to co nvince him o f the
futility o f a system refresh his memo ry warm her childho o d summers spent in the uninsulated ro o f slate was mo re po werful
than o ur demo nstratio ns.
Facing imitation St-cast stone
Pro duce r : ORSOL
Co nt act : Ricardo MACÉ
We bsit e : http://www.o rso l.fr/pro duits/parements/causse
Pro duct cat e go ry: Structural wo rk / Structure - Maso nry - Facade
De script io n :
St Cast sto ne reco vered during the expansio n o f the so uth windo ws o r creating o penings to the
extensio n wo uld have been sufficient to achieve the facing thickness was no t as impo rtant in
cutting and facing elements o f a dispro po rtio nate blo w to the expected effect.Our cho ice was
therefo re po stpo ned o n a co ncrete surface appearance sto ne that mimics the o riginal sto ne.
Co m m e nt s :
Several aspects o f the extensio n were pro po sed to o wners who cho se this reminder o f the o riginal ho use in its extensio n.
http://www.co nstructio n21.o rg/data/so urces/users/7
// Costs
Co nstructio n/refurbishment co st : 50 0 0 0 0 €
Construction and exploitation costs
Re ne wable e ne rgy syst e m s co st :
Subsidie s : 0 €
18 515,0 0 €
// Urban Environment
Urban e nviro nm e nt : Residential District away do wnto wn Saint-Cast.
Individual ho uses with garden and / o r vegetable garden o n a dirt driveway.
10 10 m 2
Land plo t are a :
Built -up are a :
10 %
Gre e n space :
900
Parking space s :
summer co mfo rt.
Car lo catio n o n duckbo ards to avo id crushing the gro und keeping a planted area with wo o den pergo la fo r
// Building Environnemental Quality
Building Enviro nm e nt al Qualit y :
indo o r air quality and health
bio diversity
wo rks (including waste management)
co nsultatio n - co o peratio n
aco ustics
co mfo rt (visual, o lfactive, thermal)
waste management (related to activity)
water management
energy efficiency
renewable energies
integratio n in the land
building pro cess
pro ducts and materials
// Contest
This refurbishment co uld co mpete in the "temperate climates and energy" catego ry as well as in the "lo w carbo n" because
we paid as much attentio n to reducing energy requirements as cho o sing bio -so urced so lutio ns.