Single Family House - Gstaad, Switzerland

Moosfangstrasse 23

3780

Gstaad, Schweiz

Architekt

Gehret Design GmbH
Gewerbestrasse 19, 3784 Feutersoey
michi@gehret.ch
41 78 737 38 85

Besitzer

Gabriela, Arani and Nick Matti
Moosfangstrasse 23, 3780 Gstaad
tuttimatti@gmail.com
+41 79 656 06 00

Bewohner


Ansprechpartner

Dr Arch. Cristina S. Polo López
SUPSI - University of applied sciences and arts of southern Switzerland
cristina.polo@supsi.ch
+41 58 666 63 14

Other Information

Visits
For individuals with an appointment.

Related publications
Swiss Solar Price 2019
Credits: Solaragentur Swiss Solar Prize 2019
Every year in Switzerland more than 2,000 agricultural holdings are abandoned. The buildings often remain unused (CVP-Mo 11.3285). A redevelopment or conversion of older buildings into residential buildings is not always possible due to the federal legal restrictions on the preservation of cultural landscapes. It is questionable what a half- decayed building can do on a planet rendered uninhabitable by global warming due to development. Gabriela Matti proves that traditional buildings can easily be combined with the latest technology with the conversion of the unused Maiensäss in Gstaad. A comprehensive renovation transformed the unused and unheated wooden house into a modern PlusEnergyBuilding, that hasn't lost its "old charm."
Energieeffizienz
4984 kWh/y

Klimazone Cfb

Höhe über dem Meer 1050 m ü.d.M.

Heizgradtage 3009

Kühlgradtage 22

Unterschutzstellung denkmalgeschützt

Ensembleschutz:
Ja

Stufe der Unterschutzstellung:
Federal legal restrictions on the preservation of cultural landscapes

Baualter 1700-1800

Letzte Sanierung:
2018

Vorhergehende Sanierungen:
0

Gebäudenutzung Residential (rural)

zusätzliche Nutzung:
NA

Gebäudebelegung:
Permanently occupied

Anzahl der Bewohner/Nutzer:
3

Gebäudefläche Nettogeschossfläche [m²]: 160,0

Gebäudetyp:
Detached house

Anzahl der Stockwerke:
2

Keller ja/nein:
Ja

Anzahl der beheizten Stockwerke:
2

Bruttogeschossfläche [m²]:
209,0

Thermische Gebäudehülle [m²]:
0,0

Volumen [m³]:
1122,0

NGF Berechnungsmethode:
SIA 416

Bauart
Solid timber wall

Außen:
Partly exposed woodwork and partly plastered.

Innen:
Partly exposed woodwork and partly plastered.

Dach:
Pitched roof

+ MEHR - WENIGER
Credits: Solaragentur Swiss Solar Prize 2019
Credits: Solaragentur Swiss Solar Prize 2019
© Daniel Baggenstos
© Daniel Baggenstos
© Daniel Baggenstos
© Daniel Baggenstos
© Daniel Baggenstos
© Daniel Baggenstos
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
MEHR SEHEN +
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
© Michi Gehret, Gehret Design
© Solaragentur Swiss Solar Prize 2019
© Solaragentur Swiss Solar Prize 2019
General view before interventions © Gehret Design
General view before interventions © Gehret Design
Old wall © Gehret Design
Old wall © Gehret Design

RENOVIERUNGS-PROZESS

Architektur

BESCHREIBUNG

The building is located in Gstaad and was originally used for agricultural purposes, but later abandoned. It was completely renovated in 2018 to become a single-family house. The project includes an extension of the basement floor (that doesn't change the external volume) for a total energy requirement of 17,600 kWh/y. The photovoltaic roof is aesthetically perfectly integrated in terms of shape and provides 154% of the energy required. The renovation of the building was largely managed by the family themselves, who took it step by step. For this reason some details are not available because they were carried out on site.
Städtebaulicher Kontext
The building is located in a rural area, surrounded by greenery and not in close contact with other buildings. In fact, it is placed in a typical alpine area.

Erhaltungszustand

Erhaltungszustand der Gebäudehülle
The building was in a state of abandonment. The exterior appearance has been preserved in the best possible way to maintain the original character of the building and not to spoil the appearance of the area. Regardless of the state of conservation, the interior structure has been extensively modified to make it liveable.
Haustechnische Anlagen vor Sanierung
Before the intervention the building had no heating system. Its function was completely different from after the renovation, in fact it was an agricutural building.

DENKMALWERT

ERHALTENSWERTE ELEMENTE
To preserve their original appearance, not all original walls have been covered with external thermal insulation. This leads to a fairly high energy index of 84 kWh/m2a (in comparison with other similar buildings). The original shape of the roof has been maintained thanks to an integrated photovoltaic system that works as a roof cover as well. In the demolition/new plan it is possible to see exactly which parts were maintained (black) and which are new (red).
Denkmalwert und wie er bestimmt wurde
The building is located in an area with federal legal restrictions on the preservation of cultural landscapes, so it is important to keep its original appearance in the environment. The focal elements for the preservation of the building are mainly the external ones. In fact, due to the total change in function, it has not been possible to maintain the interior appearance of the building (it has been made livable and therefore requires certain technologies and spaces). The main facade, the shape of the roof and the windows are the elements that have been taken into consideration most for the preservation, as they are the most visible and characteristic elements of the building. The house is composed by two floors and a basement. The original function provided a double height between ground and 1st floor, which has been maintained. An extension of the basement floor was carried out during the renovation. The typical 4-pitch roof, with its peculiar shape, has been completely renewed but maintained in the original form.

Ziel der Sanierung

Renovation + Extension
It has been decided to give new life to the otherwise abandoned building. The total change in its function has led to compromises to combine energy efficiency with the preservation of its original appearance. Walls, floor slabs, roofing, heating and electricity systems have been affected.
Gab es eine Änderung der Nutzung?
Transformation of an old unused and unheated agricultural building into a residential single family house.
Gewonnen Erkenntnisse / besondere Erfahrungen
This renovation of PlusEnergieBau shows how tradition and integrated photovoltaics can complement each other. It teaches us how to bring old characteristic buildings back to life, increasing their efficiency but maintaining as much as possible their original charm.
Beteiligte Akteure
Architekt
Gehret Design GmbH
Gewerbestrasse 19, 3784 Feutersoey
michi@gehret.ch
Tel. 41 78 737 38 85
Energieberater
SolarUp Energie, Christoph Ogi
Cheseryplatz 3, 3780 Gstaad
info@solarup.ch
Tel.+41 33 748 10 31
Statiker
Egger Ingenieure AG
Mettlenstrasse 49, 3780 Gstaad, Schweiz
info@eggering.ch
Tel.+41 (0)33 748 84 22
Andere
Benz Hauswirth AG
Gstaadstrasse 72, 3792 Saanen
info@benzhauswirth.ch
Tel. 41 33 748 04 44
Eingesetzte Software/Berechnungstools
Folgte die Sanierung einer spezifischen Methode? MuKEn-Standard Exemplary solar architecture + large passive use
Energiebilanz SIA 380/1
Hygrothermische Bewertung No
Life Cycle Analysis (LCA) No
Anderes No

SANIERUNGS-LÖSUNGEN

Außenwände

Solid timber wall - external insulation

Stone wall

Solid timber wall - internal insulation

Solid timber wall - external insulation

Three facades have been clad with external thermal insulation while front facade has been clad with a thinner inner layer to preserve its original external appearance. It was chosen to provide external insulation for most of the building to achieve better energy efficiency results, but to maintain at least the main façade. The U-value post intervention is 0.2 W/m2K. There are no evaluation of the U-value before intervention, due to the previous function of the building.

At 84 kWh/m2a, the energy index is relatively high compared with other similar buidings, indicating suboptimal insulation values. However, it was a balancing of interests that led to the original front wall not being covered with external thermal insulation. This made it possible to maintain the original character of the building.

U-Wert (nach Sanierung) [W/m2K]: 0,2 W/m²K
Mehr Details
Aufbau Bestandswand
Wood - Original wood has been partially maintained.:
150 mm
- Originally it was a one layer wall.:
0 mm
Aufbau sanierte Wand
Wood panelling - External finish simulates the original one.:
30mm
Air gap - Cold facade.:
30 mm
Other - Wind paper.:
0 mm
Insulation - Stone wool.:
160 mm
Other - Vapour barrier.:
0 mm
Wood - Original wall has been cladded. :
150 mm
Stone wall

External walls touching the ground are stone made. They are externally insulated as well as the solid timber ones. The transition between timber wall and stone wall is protectet from water infiltration thanks to a moisture barrier.

The original structure is maintained. The original wall was prepared prior to the addition of the insulation by levelling and reinforcing through the application of a layer of concrete. A moisture barrier has been applied. The wall on the back side of the house, where the basement is fully below ground, is part of the extension and is a simple concrete structure with XPS insulation and a waterproof barrier.

U-Wert (nach Sanierung) [W/m2K]: 0,2 W/m²K
Mehr Details
Aufbau Bestandswand
Stone - Original stone structure.:
370 mm
- Original one layer wall.:
0 mm
Aufbau sanierte Wand
Stone - Cladding:
40mm
Insulation - XPS:
160 mm
Concrete - Structure:
220 mm
Stone - Original structure:
150 mm
Solid timber wall - internal insulation

Three facades have been clad with external thermal insulation while front facade has been clad with a thinner inner layer to preserve its original external appearance. It was chosen to provide external insulation for most of the building to achieve better energy efficiency results, but to maintain at least the main façade. No problems were found with humidity.

At 84 kWh/m2a, the energy index is relatively high compared with other similar buildings, indicating sub-optimal insulation values. However, it was a balancing of interests that led to the original front wall not being covered with external thermal insulation. This made it possible to maintain the original character of the building.

U-Wert (nach Sanierung) [W/m2K]: 0,2 W/m²K
Mehr Details
Aufbau Bestandswand
Wood - Original wood has been partially maintained.:
150 mm
Aufbau sanierte Wand
Wood - Original wood structure is exposed:
150mm
Insulation :
80 mm
Air gap :
30 mm
Wood panelling :
30 mm


Fenster

Triple glazing wood windows

Triple glazing wood windows

Windows have been renewed to optimise thermal comfort but the original position and shape have not been altered. Some windows contains outer shutter, while others contains roller blinds.

Triple glazing guarantees a high comfort level. Only one window has been added to reach the amount of light necessary in the kitchen space.

Bestandsfenster U-Wert Glas [W/m2K]: 3,0 Neues Fenster U-Wert Glas [W/m2K]: 0,7 Bestandsfenster U-Wert Rahmen [W/m2K]: 3,0 Neues Fenster U-Wert Rahmen [W/m2K]: 1,35
Mehr Details
Fenstertyp Bestand Casement window
Verglasungsart Bestand Single
Verschattung Bestand NA
Ungefähres Einbaujahr 1900
Neuer Fenstertyp Casement window
Verglasungsart des neuen Fensters Triple
Verschattung des neuen Fensters Outer shutter and roller blinds.
Neuer Energiedurchlassgrad g [-] 55,0

Weitere Maßnahmen

DACH

ERDGESCHOSS

SONSTIGES

DACH

The roof has been renovated with the addition of external thermal insulation and an integrated photovoltaic system that covers 154% of the building's energy requirements.

The intervention keeps the original shape of the roof intact, demonstrating that conservation and innovation can work together.

U-Wert (nach Sanierung) [W/m2K] 0.17
Mehr Details
Aufbau Bestandsdach
Shingles - One layer wood shingles roof.:
150 mm
- Exposed wooden work.:
0 mm
Aufbau saniertes Dach
Other - Integrated PV system.:
6 mm
Other - Under-roof :
0 mm
Other - Insulation Flumroc PARA:
160 mm
Other - Ampatex DB 90 (vapour barrier and airtight layer):
0 mm
Other - Wood board:
24 mm
Other - Insulation and wooden battens.:
120 mm
Other - Wood surface.:
10 mm
ERDGESCHOSS

Floors have been completely replaced with massive concrete slabs. This section describes the basement slab (touching the ground) to show the layering that involves the envelope of the building.

The massive intervention is necessary. In fact, the pre-existing slabs were in no way recoverable. The inclusion of a coils heating system allows a better heat distribution and therefore greater thermal comfort for the inhabitants.

U-Wert (nach Sanierung) [W/m2K] 0.17
Mehr Details
Aufbau Boden/Kellerdecke im Bestand
Floor joists - Wood:
150 mm
Finish - Wood:
20 mm
Aufbau Boden/Kellerdecke nach Sanierung
Finish - Wood (oak):
25 mm
Concrete slab - Lean concrete:
80 mm
Insulation - SwissporLUXIT EPS-T:
20 mm
Concrete slab - Basement slab:
200 mm
Other - Separating layer:
0 mm
Insulation - XPS :
180 mm
Concrete slab - Lean concrete:
50 mm
SONSTIGES

Ground floor and first floor slabs have also been replaced, as the original ones were not in a state of preservation (static and comfort requirements). The wood finish covers most of the floor, excluding the stairs area which has a stone finish.

The wood finish conforms to the final appearance of the house, but does not retain its original appearance. The inclusion of a coils heating system allows a better heat distribution and therefore greater thermal comfort for the inhabitants.

HVAC

HEIZUNG

BRAUCHWARMWASSER

HEIZUNG

The building was not heated. With the renovation an air/water heat pump was installed.

The intervention inside the building was massive due to the absence of comforts in the original construction (change of function). An air-water heating system has been chosen which, through the coils, allows better thermal comfort as the heat is evenly distributed inside the spaces.

Mehr Details
Heizungssystem nach Sanierung
Art der Heizung Heat pump
Brennstoff Electricity
Wärmeverteilung Radiating floor
Nennleistung 6 kW
BRAUCHWARMWASSER

The building did not have domestic hot water previously. The heat pump also provides for this.

The intervention inside the building was massive due to the absence of comforts in the original construction (change of function). An air-water heating system has been chosen which, through the coils, allows better thermal comfort as the heat is evenly distributed inside the spaces.

Mehr Details
Brauchwarmwasserbereitung nach Sanierung
Typ with heating system
Brauchwasserspeicher Ja
Wärmerückgewinnung aus Brauchwasser Ja

ERNEUERBARE ENERGIE

Photovoltaik

Photovoltaik

Roof-integrated solar system, so the PV-panels function as roof cover as well. This intervention is included in the Swiss Solar Prize 2019. It was decided to install the PV system on the roof to take advantage of its favourable position and avoid damaging the green landscape with a ground system. Placing it on the roof takes advantage of an existing element in the panorama.

The building in alpine Gstaad, which was originally used for agricultural purposes but later abandoned, was comprehensively renovated in 2018. The total energy requirement of the now spacious detached house (EFH) is 17,600 kWh/a. The exemplary integrated 32 kW PV system generates around 27,000 kWh of CO2-free solar electricity annually. The resulting homogeneous roof surface corresponds to the simple external appearance of the building. This PlusEnergieBau renovation shows how tradition and integrated photovoltaics can be combined aesthetically very well. Overall, the EFH has an energy supply of 154%. A 13 kWh battery storage increases the own consumption.

Mehr Details
Photovoltaic System
Type Monocrystaline
Collector area 178,0 m²
Total nominal power 31,7 kW
Elevation angle 39,0
Azimuth 44,0
Overall yearly production 27000,0 kWh
Heating contribuition 4984,0 kW
DHW contribuition 2492,0 kW
Cooling contribuition 0,0 kW
Lighting contribuition 3916,0 kW

Energieeffizienz

Energieeffizienz
Energieausweis MuKEn-Standard Exemplary solar architecture, large passive use
Freiwillige Zertifikate Nein
Energievrabrauch
Heizung
Berechnungsmethode Steady state simulation (e.g. EPC, PHPP)
Energieverbrauch nach Sanierung 4984 kWh/y

Primärenergie
Berechnungsmethode Steady state simulation (e.g. EPC, PHPP)
Energieverbrauch incl Brauchwarmwasser Ja
Energieverbrauch nach Sanierung 17'576 kWh/y

Raumklima

Temperatur

The thermal comfort of the occupants is guaranteed thanks to the new walls, roof and floor insulation and the new heating system.

Indoor Air Quality

The building has excellent natural ventilation, so it does not require a mechanical ventilation system. Indoor air doesn't need any intervention due to the privileged position and the good natural air quality.

Daylight

Daylight does not change compared to pre-intervention due to the original size of the openings which was determined by the existing structure.

akustischer Komfort

Triple glazing windows also improved the acoustic comfort of the house, but the location doesn't need particular expedients. The choice of triple glazing is due to thermal aspects.

Erhaltung von Ausstellungsstücken

NA

Kosten

Finanzielle Aspekte

There are no financial aspects available.

Betriebskosten
Lifecycle cost
Nein