Glaserhaus - Affoltern im Emmental, Switzerland

Eggerdingen 7

3416

Affoltern im Emmental, Switzerland

Architect

Anliker Christian, Arch/Innenarchitekt SWB
Gerechtigkeitsgasse 73, 3011 Bern
ch.anliker@bluewin.ch
+41 31 311 49 06

Owner

Christian & Elisabeth Anliker
Eggerdingen 7, 3416 Affoltern
ch.anliker@bluewin.ch
+41344350033

Contact Details

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
Contact the Owner

View from south-west © C. Martig
The aim of the project and the associated construction measures is to repair the existing and restore the original condition. The floor plans will be spatially and functionally separated, with the aim of consistently uncovering the core building from 1765 on all floors. This restoration is connected with the aim of preserving the overall appearance of the building, repairing the roof, facades and surroundings and carefully restoring the prestigious south facade. From a technical point of view, the building is solidly stabilised and energetically brought up to the latest standards. The project was developed with the involvement of the cantonal monument preservation authorities. Several meetings and inspections took place, on the basis of which the project was further developed in accordance with the requirements of the preservation of historical monuments.
Energy performance
26,64 kWh/m2.y

Climate Zone Cfb

Altitude 775 m a.s.l.

HDD 171

CDD 0

Protection level Listed

Conservation Area:
No

Level of Protection:
Protected at cantonal level (Canton Bern)

Building age 1700-1800

Year of last renovation:
1980

Year of previous renovation:
1888

Building use Residential (rural)

Secondary use:
NA

Building occupancy:
Permanently occupied

Number of occupants/users:
4

Building area Net floor area [m²]: 985,0

Building typology:
Detached house

Number of floors:
4

Basement yes/no:
Yes

Number of heated floors:
2

Gross floor area [m²]:
1159,0

Thermal envelope area [m²]:
910,0

Volume [m³]:
1880,0

NFA calculation method:
SIA 416

Construction type
Timber frame

External finish:
Exposed woodwork

Internal finish:
Exposed woodwork

Roof type:
Pitched roof

+ MORE - LESS
View from south-west © C. Martig
View from south-west © C. Martig
Top view from south-east © C. Heilig
Top view from south-east © C. Heilig
South slope © C. Heilig
South slope © C. Heilig
Night view © C. Anliker
Night view © C. Anliker
Environment © C. Anliker
Environment © C. Anliker
General view before interventions © C. Anliker
General view before interventions © C. Anliker
East view before interventions © C. Anliker
East view before interventions © C. Anliker
South front  before interventions © C. Anliker
South front before interventions © C. Anliker
South front  before interventions © C. Anliker
South front before interventions © C. Anliker

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

The building in Affoltern in the Emmental/BE is an imposing glazier's house built in 1765. A first renovation took place in 1888. The last renovation, which was completed in 2015, is a shining example of how, despite extensive preservation orders, the total energy requirement can be low and solar power generation high. The building with a very compact volume, is located in an open country area, in the middle of cultivated fields not far from the centre of the village Affoltern in Emmental. It is completely free and has a very good exposure. The original structure consists in quarry stone foundations and a stand/beam construction. The original woodwork facades were shingle-covered during the 1888 renovation, as shown in pre-intervention photos. For the 2015 renovation the decision is to remove the shingle cladding to make the stud construction visible again where possible and keep it in its original grey tone. The iconic south façade, which consists in a traditional window front, has a particular value in terms of monument conservation.
Urban context
Isolated building in a rural setting.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION
The 250 years old house is, as the name “Glaserhaus” (glazier house) explain itself, important for her iconic south front, which appears with a multitude of windows. The three-storeys house is crowned by a roundabout. The eaves-sided upper floor arcades are closed. The house shows also contoured woods (braided bows) and a distinguished grey frame. Unfortunately, the general state of the building was near to collapse, imposing a big intervention. The shape and the volume of the building have primary relevance on the conservation of this historic house, together with the south front. A massive part of the structure was no longer safe, including the roof. It has been renovated following the original quarter hipped shape.
Heritage Value Assesment
The new roof presents a recognizable photovoltaic system that perfectly follows the original shape of the roof. We start from the fact that the original roof structure was in a very decadent state. During their life buildings follow the development of building techniques, taking the best of each of the previous eras. History changes from thatched roofs, to shingle roofs, to flat tiles. As a logical consequence in a building subject to environmental protection and taken as a symbol to maximize energy efficiency on historic buildings, an integrated PV system is the best technology on the market. A question arises spontaneously: why so much effort to restore the south façade to its original state instead? The house has an important relevance in terms of individuals, due to the fact that it belonged to a well-known dynasty of glaziers and carpenters (Heiniger). This reasonably makes the windows front symbolic, deserving a special treatment. Some roof openings were added to reach a recommended light supply, since the existing openings where not enough.
Heritage Assessment Files

State of repair

Conditions of the envelope
The building stood empty for a long time in the 20th century and began to deteriorate. The current owners found the house, which was classified as the highest level of protection by the canton of Bern's monument preservation department, in a desolate condition: the roof was leaky and the entire frame construction from the ground floor to the roof was badly warped. The existing building is marked by subsidence: the pier construction is warped into the roof construction due to insufficient load-bearing capacity and strength of the peripheral quarry stone foundations on the ground floor. The core building from 1765 comprises on the ground floor in front of the sandstone wall on the slope side the kitchen, the vaulted cellar with the stone staircase as well as the entrance and 2 rooms; it has only a limited foundation. Due to the pressure of the slope, the vaulted cellar has cracks; the lintel has cracked. The condition of the foundation of the building requires renovation. The most important measure is to install a continuous transverse stabilisation in the rear area of the quarry stone wall on the slope side. In order to enable the relevant concrete work to be carried out in the ground under the existing building, the transverse stabilisation requires appropriate excavation.
Description of pre-intervention building services
Services were in a poor state and no longer usable. The transverse stabilization in the ground floor is to be designed as a hollow concrete body with inherent stability and then used as a technical room for the entire building. This will ensure that the cross-stabilization has the desired effect from a structural point of view and that the building services installations can be combined outside the original floor plan.

Aim of retrofit

Renovation
Since its construction, the building has always been inhabited but has never had a direct link with the cultivated fields around it. In 2012 the new owners had to intervene both to improve energy efficiency and to improve the statics with the aim to restore the house to its original appearance. The most important measure was the structural and constructive overhaul of the house. The project was developed with the involvement of the cantonal monument preservation authorities. Several meetings and inspections took place, on the basis of which the project was further developed in accordance with the requirements of the preservation of historical monuments. Finally the building application documents, which were very detailed in terms of monument protection by the architectural firm, were analysed by the competent cantonal office "Denkmalplege", which did not make any observations and allowed the building to be constructed as planned.
Lessons learned
The project was approached with extreme seriousness and informal contacts with the competent authorities, so that all the prerequisites were in place to deal with a project of this magnitude and no particular problems were encountered during its execution.
Stakeholders Involvement
Public sector
Denkmalpflege (Monument preservation office) Canton Bern
Schwarztorstrasse 31, 3001 Bern
denkmalpflege@be.ch
Tel.+41316334030
Architect
Anliker Christian, Arch/Innenarchitekt SWB
Gerechtigkeitsgasse 73, 3011 Bern
ch.anliker@bluewin.ch
Tel.+41 31 311 49 06
Conservation Consultant
Anliker Christian, Arch/Innenarchitekt SWB
Gerechtigkeitsgasse 73, 3011 Bern
ch.anliker@bluewin.ch
Tel.+41 31 311 49 06
Energy Consultant
Lukas Meister, clevergie gmbh, Region Bern
Gemeindehaus 118, 4954 Wyssachen
info@clevergie.ch
Tel.+41 62 966 00 66
Services Engineer
Lukas Meister, clevergie gmbh, Region Bern
Gemeindehaus 118, 4954 Wyssachen
info@clevergie.ch
Tel.+41 62 966 00 66
Other
Habisreutinger Gebäudehülle GmbH
Brückenstrasse 6a, 4950 Huttwil
info@h-g.ch
Tel.+41 62 962 440
Tools used
Was the renovation process done following a specific methodology? Minergie P refurbishment but without certification
Energy calculation SIA 380/1
Hygrothermal assessment No
Life Cycle Analysis (LCA) No
Other No

RETROFIT SOLUTIONS

External Walls

Timber wall

Timber wall

Facades have been restored to their very first appearance. The state right before the intervention presents a shingle cladding which has been added in a later intervention during the 250 years long life of this building. For this reason, the renovation shows a wood cladding that replicates the original one and that will turn grey in a few years, giving back to the house her old charm. Some parts, visible on the south facade, are actually original. The building was in a very decadent state before renovation. For this reason, the structure has been largely renovated, whereas all the internal cladding consists in original reused wood.

As far as the energetic improvement is concerned, only the southern front was not thermally insulated due to protection constraints of historic buildings, that in this case were severe regarding the maintaining of the window front as close as the original as possible (the intervention was possible directly on windows, as described in the dedicated part of this article). Other facades improved with the insertion of the solar thermal insulation between the wooden rafters, reaching the Minergie-P standard.

U-value (pre-intervention) [W/m2K]: 3,0 W/m²K U-value (post-intervention) [W/m2K]: 0,16 W/m²K
More Details
Original wall build-up
Wood - solid wood planks:
40 mm
Wood - Girders and mullions:
200 mm
Retrofitted wall build-up
Wood - Planks:
20mm
Other - Ventilation and battens:
70 mm
Wood - Softwood fibreboard:
40 mm
Insulation - Wood Wool and beams:
160 mm
Wood - USB:
20 mm
Insulation - Wood Wool and battens:
40 mm
Wood - Planks:
25 mm


Windows

Wood windows

Wood windows

Replica windows with the same characteristics and dimensions as the previous ones were made, but which could accommodate a triple glazing (reproduction of the frame and crossbar profiles). For reasons of monument protection, the traditional window front with wooden bars remained without insulation. Only the other windows received new insulating glazing. The hand-made window panes installed by the master glazier in the 18th century found a new use in the interior.

Most of the windows are located on the large south front and due to protection constraints their appearance could not be changed: for this reason replica windows with the same characteristics and dimensions as the previous ones were made, but which could accommodate a triple glazing (reproduction of the frame and crossbar profiles).

Existing window U-value Glass [W/m2K]: 3,0 New window U-value Glass[W/m2K]: 0,7 Existing window U-value Frame [W/m2K]: 3,0 New window U-value Frame [W/m2K]: 1,0
More Details
Existing window type Casement window
Existing glazing type Single
Existing shading type NA
Approximate installation year 1888
New window type Casement window
New glazing type Triple
New shading type NA
New window solar factor g [-] 45,0

Other interventions

ROOF

GROUND FLOOR

ROOF

The roof construction shows deformations caused by subsidence, in some places it is defective. The deformations are straightened, the defectiveness is remedied, especially by straightening the existing purlins and rafters. The existing roof structure is supplemented by a new rafter layer and wooden formwork to ensure the load-bearing capacity and rigidity of the entire system and to achieve the required insulation thickness. The roof is insulated throughout, which is indispensable in the cross-section to avoid energy inefficiency and to avoid areas of potential cold bridges. In addition, the existing storage use of the platform above the core building does not require any heating for energy reasons, but nevertheless a certain constancy with regard to room temperature and air humidity.

The roof shape is returned to its original simple form by removing the 20th century skylight and the roof elevation above the entrance to the storage room. The roof consists in a matt black slate-like photovoltaic system.

U-value (pre-intervention) [W/m2K] 3 U-value (post-intervention) [W/m2K] 0.16
More Details
Original roof build-up
Tiles - Flat tiles:
15 mm
Other - Wood batten and counter-battening:
80 mm
Other - Beans:
200 mm
Retrofitted roof build-up
Other - PV integrated system:
20 mm
Other - Wood batten and counter-battening:
110 mm
Other - Underroof / three-layer board (wood):
42 mm
Other - Insulation:
180 mm
Other - Wood board:
27 mm
Other - Wood beams:
180 mm
GROUND FLOOR

Without thermal insulation and without sound insulation, board cladding of approx. 40 mm, partly on the ground and partly on wooden beams. Totally renovated.

The details were discussed with the cantonal office taking into account the height problems of the premises.

U-value (pre-intervention) [W/m2K] 1 U-value (post-intervention) [W/m2K] 0.16
More Details
Original groundfloor build-up
Other - Earth:
400 mm
Finish - Wood:
40 mm
Retrofitted groundfloor build-up
Insulation - XPS:
150 mm
Concrete slab - Concrete slab:
200 mm
Insulation - floor sound insulation:
30 mm
Finish - Floor:
30 mm

HVAC

HEATING

VENTILATION

AIR CONDITIONING

DOMESTIC HOT WATER

HEATING

The heat is generated using two geothermal boreholes made of polyethylene pipes which are laid in the ground with a deep bore hole. The heat for the heating system is generated with a water heat pump. The hot water preparation is carried out by a 1'000l combi storage system. The heat pump, the heating group, the free-cooling function and the DHW preparation are regulated or controlled by the projected regulation. The heat load occurring in summer is extracted from the building with the floor heating pipes and released into the ground via the geothermal probe. For room heating in winter and cooling in summer, a separately controllable and shut-off underfloor heating group is provided on the ground floor, 1st floor and first floor. The heat is emitted or extracted with a conventional underfloor heating system, inserted in the underlay floor. The individual room regulation is ensured by electric room sensors. Rooms with minimum room heights are heated with radiators, the wet areas are additionally heated with a towel radiator. The heat distribution takes place via a radiator heating group which can be separately regulated and switched off from the heat generator or storage tank. A Step oven under preservation order, with built-in heating register is also operated via the radiator heating group. The individual room regulation is ensured by thermostatic valves.

The only element of the heating system that touches on the protection of historical monuments is the step oven on the ground floor, whose model was chosen according to the requirements of historical monuments. An existing traditional tiled stove with a heated bench - a so-called Swiss step stove - was incorporated into the heating circuit via a subsequently installed heating register.

More Details
New primary heating system New secondary heating system
New system type Heat pump Stove
Fuel Electricity Biomass
Distribuition system Radiating floor Air
Nominal power 17 kW NA kW
VENTILATION

The building has ventilation with opening of windows, no mechanical ventilation

The airtightness of the windows has been largely improved while maintaining the appearance in accordance with the historical monuments.

More Details
Original roof build-up New ventilation system
Type ventilation system NA (Natural)
Type flow regime NA (Natural)
Heat recovery No
Humitidy recovery No
Nominal power 0 kW
Electric power 0,0 kW
Control system No
AIR CONDITIONING

The heat load occurring in summer is extracted from the building with the floor heating pipes and released into the ground via the geothermal probe. In summer, the building can also be passively cooled with the system. The water circulating in the underfloor heating absorbs excess heat and transfers it via a heat exchanger to the brine circuit and then to the ground.

The cooling system is integrated in the heating distribution (radiating floor) and doesn’t involve any intervention that requires conservation compatibility.

More Details
New cooling system
Type Heat pump
Distribuition system Radiating floor
Nominal power 13.4 kW
Electric power 3,62 kW
DOMESTIC HOT WATER

The heat is generated using two geothermal boreholes made of polyethylene pipes which are laid in the ground with a deep bore hole. The heat for the heating system is generated with a water heat pump. The hot water preparation is carried out by a 1'000l combi storage system.

The DHWsystem is integrated in the heating that doesn’t involve any intervention that requires conservation compatibility. An existing traditional tiled stove with a heated bench - a so-called Swiss step stove - was incorporated into the heating circuit via a subsequently installed heating register.

More Details
New DHW system
Type with heating system
Hot_water_tank Yes
With heat recovery No

RENEWABLE ENERGY SYSTEMS

Photovoltaic

Geothermal

Photovoltaic

This intervention demonstrates the potential PV implementation in a protected building and within a sensible landscaping heritage. The solar tiling completely replace the roof surface. The homogeneous solar cladding, extended to the whole roof area, creates a clear recognizability/expression of PV respecting the general lines and the morphology of the pre-existing building typology. Twelve skylights that can be opened are integrated into the solar roof to increase daylighting inside the building and to allow natural ventilation. The project was awarded with the swiss solar price 2016.

On the roof of the special craftsmen's house, which is a listed building, a fully integrated photovoltaic system was installed. The modules take over the function of the water-bearing layer, therefore it is an in-roof system.

The frameless modules of the Swiss company Meyer Burger were used. In order to be able to actively cover the edges of the roof, so-called "Crea modules" from Meyer Burger (made to measure) were also added. In order to maintain a homogenous black appearance of the roof surface, solar-look printed single-pane safety glass was used on the northern mitre sign.

More Details
Photovoltaic System
Type Monocrystaline
Collector area 550,0 m²
Total nominal power 85,0 kW
Elevation angle 45,0
Azimuth 85,0
Overall yearly production 90493,0 kWh
Heating contribuition 12300,0 kW
DHW contribuition 0,0 kW
Cooling contribuition 0,0 kW
Lighting contribuition 13940,0 kW
Geothermal

Two geothermal probes placed at a depth of 180 meters extract heat from the ground, which is raised by the heat pump to a temperature level suitable for space heating and hot water preparation. In summer, the building can also be passively cooled with the system. The heat is generated using two geothermal boreholes made of polyethylene pipes which are laid in the ground with a deep bore hole. The heat for the heating system is generated with a water heat pump. The hot water preparation is carried out by a 1'000l combi storage system. The heat pump, the heating group, the free-cooling function and the DHW preparation are regulated or controlled by the projected regulation.

The only element of the heating system that touches on the protection of historical monuments is the step oven on the ground floor, whose model was chosen according to the requirements of historical monuments.

The heat is emitted or extracted with a conventional floor heating system, inserted in the underlay floor. The individual room regulation is ensured by electric room sensors. Rooms with minimum room heights are heated with radiators, the wet areas are additionally heated with a towel radiator.

More Details
Geothermal System
Type Vertical loop
Exchange area 696,0 m²
Overall yearly production 26000,0 kWh

Energy Efficiency

Energy Performance
Energy performance certificate: No
Voluntary certificates: The owners renovated the building strictly in accordance with the Minergie-P standard (but without an official label). This construction standard corresponds to Passivhaus in DE or CasaClima Gold in Italy. Spread over all sides of the roof, the 89.4 kW and 550 m2 PV installation produces 90,500 kWh/y. Until the full completion of the semi-detached dwelling, only two people live and work in the building, which explains the effective surplus of 80'800 kWh/y injectable into the public grid. The high quality of PEB (Plus Energy Building) renovation ensures 345% self-production.
Energy Use
Heating
Consumption_estimation_Calculation_method: On-stie monitoring
Documents:
20160414_scs_Verbrauch Wärmepumpe 2015.pdf
Consumption heating
20160414_scs_Verbrauch Wohnung EG DG 2015.pdf
Consumption electricity

Consumption_estimation_Before: 180000 kWh/y
Consumption_estimation_After: 26,64 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: Steady state simulation (e.g. EPC, PHPP)
Documents:
Dati energetici Affoltern.pdf
Energetic data

Consumption_estimation_Including_DHW: Yes
Consumption_estimation_Before: 273100 kWh/y
Consumption_estimation_After: 77932 kWh/y
Measured Parameters
Internal Climate
Type_of_monitoring: Punctual
Description: The building before the renovation was not at all airtight, considering the gaps between the wooden boards that make up the previous shell. The realisation of the new shell in accordance with the SIA 180 standard, which requires airtightness, improves radically the quality of internal climate. The heating system is reversible and permits to cool the inside spaces during the hot summers.

Construction
Type_of_monitoring: Continuous
Description: No construction or indoor air quality monitoring is performed. For the temperature there are modern systems with sensors (hot-cold). Monitoring of performances of PV systems and energy improvements are available at: https://www.energie-cluster.ch/de/deklariert-ch/plusenergiegebaeude/efh-anliker-sanierung-eggerdingen-7-3416-affoltern-im-emmental-3495.html

Internal Climate

Temperature

The building is divided in two different heating zones: the normal one in the core and the rest. The existing storage use of the platform above the core building does not require any heating for energy reasons, but nevertheless a certain constancy with regard to room temperature and air humidity.

Indoor Air Quality

The building before the renovation was not at all airtight, considering the gaps between the wooden boards that make up the previous shell. The realisation of the new shell in accordance with the SIA 180 standard, which requires airtightness, improves radically the quality of internal climate. The heating system is reversible and permits to cool the inside spaces during the hot summers. For the temperature there are modern systems with sensors (hot-cold). Twelve skylights that can be opened are integrated into the solar roof to allow natural ventilation and to increase daylighting inside the building.

Daylight

The lighting in the building is largely provided by natural light, thanks to the arrangement of the windows, especially those on the south front, where the fully inhabited and heated part of the building is located, which bring plenty of light inside. In the semi-heated/unheated areas of the roof level, the skylights integrated in the photovoltaic roofing bring the necessary light without having to use electricity during the day.

Acoustic Comfort

The sound insulation has been significantly improved compared to the previous situation, with a minimum of impact insulation but within certain limits due to the local height.

Artifact Conservation

The wooden planks, used for the previous casing, were cut from whole trees and had widths of up to 84 cm (tree trunk). These were replaced and some of them with paintings, 1m x 50 cm, were given to the Landesmuseum.

Costs

Financial Aspects

The goal of the refurbishment was to re-use these building that was in a really bad estate. Costs includes all the action to do this.

Investment Costs
Total investment costs
2.8 mio CHF (total)
Amount includes: Building and surroundings

Cost of energy related interventions:
745'000.- CHF (total)
Amount includes: Insulation floor, walls, roof, windows, PV, heat pump and borholes
Running Costs
Total annual energy cost
180.- per month (about 2160 CHF/year) (total)

Annual heating cost
about 1500.- CHF (total)
(includes DHW) Yes

Annual electricity cost
about 660.- CHF (total)

Lifecycle cost
No

Environment

Water Management

A cistern has been built that takes both rainwater and water from a small spring in the ground (used approx. 8l/min). An overflow brings the excess water to a nearby stream.

Transport and Mobility

It is planned to build a charging station for electric cars, at the moment that the owners will change vehicles (private car as they live in the countryside). There is a place to lay batteries but they are not yet laid. The batteries would be used to store electricity both for domestic use and for the electric car.

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