GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Hof 6, Schwarzenberg, Voralberg, Austria

Schwarzenberg, Austriche

Architect

Thomas Mennel

Hof 6, Schwarzenberg

Owner

Thomas Mennel

Hof 6, 6867 Schwarzenberg, Austria

User

Contact Details

Tobias Hatt

Energieinstitut Vorarlberg

tobias.hatt@energieinstitut.at

Other Information

by the owner itself

Related publications
book “ Umgebaute Bauernhäuser in Vorarlberg” by Florian Aicher und Hermann Kaufmann

The former farm house and later on home of the painter Angelika Kaufmann was almost 450 years old, when the architect and new owner Thomas Mennel decided to restore the building and play with it's given qualities. He kept the outward appearance and changed its internals into a spaceship full of places to experience, with its different light and shades - it is a playground and an oasis in the same.

GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Energy performance

73 kWh/m2.y

Climate Zone cfb

Altitude 700

HDD 4256

CDD 13

Protection level Listed

Conservation Area:
Oui

Level of Protection:
the former main-/living part of the house has a heritage protection

Building age 1600-1700

Year of last renovation:
2013

Year of previous renovation:
2008

Building use Residential (rural)

Secondary use:
NA

Building occupancy:
Permanently occupied

Number of occupants/users:
5

Building area Net floor area [m²]: 300,0

Building typology:
Detached house

Number of floors:
3

Basement yes/no:
Oui

Number of heated floors:
1

Gross floor area [m²]:
337,0

Thermal envelope area [m²]:
0,0

Volume [m³]:
1000,0

NFA calculation method:
NGF (de)

Construction type

Solid timber wall

External finish:
Exposed woodwork

Internal finish:
Wood panelling

Roof type:
Pitched roof

+ MORE - LESS

after the renovation, main building, Copyright © Roswitha Schneider

after the renovation, former barn, Copyright © Roswitha Schneider

Ansicht Nord - Courtesy of Arch. Thomas Mennel

Ansicht Süd - Courtesy of Arch. Thomas Mennel

Ansicht West - Courtesy of Arch. Thomas Mennel

Ansicht Ost - Courtesy of Arch. Thomas Mennel

after the renovation, Copyright © Thomas Mennel

after the renovation, Copyright © Roswitha Schneider

before the renovation, Copyright © Thomas Mennel

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

The farmhouse was built in 1646 in log construction and was home of the painter Angelika Kaufmann. The living part of the house has been restored in 2008 and the affiliated barn was rebuild in 2013. The traditional renovation of the front building was done in the same architectural style as the existing. After the renovation two families could live in it. During the conversion of the barn their future residents lived transitionally in the loft. The barn has now been adapted, not into an ordinary residential area as it is common, but as a kind of glass house inside the barn, which now offers room for a family of four. The existing and supporting structure of the barn has been partially preserved and at the outer wall it will serve as a protective layer for this living area in the future. The timber framing of the barn has been partially (at the wall and roof) uncovered and simply covered with glass elements from the outside. An additional double glazing from the inside increases the thermal protection. Sliding wooden elements on the outside can provide the necessary shading. The many openings in the shell ensure that lots of light gets inside and increase or preserve the view to the outside. The staggered ceiling sequence is essentially developed from the light guidance. Where previously one family lived on 180m², now two families live on 337m². A thermal solar system supports the pellet heating and tiled stove, especially in the transition season and summer.

Urban context

The house is situated close the village centre in Schwarzenberg, wich has 1800 inhabitants.

Heritage Assessment Files

Bescheid Bundesdenkmalamt gemäß Denkmalschutzgesetz

State of repair

Conditions of the envelope

The almost 60 year old Eternit-roof of the building was leeking, the wooden shingles were highly weathered, there were gaps between the basement, first and second floor and the roof, which made the living uncomfortable.

Description of pre-intervention building services

The old house had a oil-fueled heating system with radiators. There was no heating in the barn.

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION

The orientation of the building Hof 6 and the other buildings in the core centre of Schwarzenberg are responsible for the historic street layout. The facade with it's traditional woodden shingles needs to be preserved.

Heritage Value Assesment

Most buildings in the village center of Schwarzenberg are in terms of detailled design of great wealth, and not just in appearance, but also in the arrangement and equipment of the interiors, as far as they are still in their original condition. Of particular note is the uniformity of the buildings. This is not just because of the same construction time immediately after the great fire of 1755 but also due to the independent handicraft tradition of the Bregenzerwald and the prosperity of the population at that time. Hof 6 was the house of Angelika Kauffmann (30.10.1741 - 5.11.1807) - a famous swizz-austrian paintress. It is a two-storey block building on masonry ground floor basement zone with a saddle roof over two attic floors. On the street side (East facade) was the residential wing, at the west side the economic wing. The facades of the residential part had wooden shingle clad with pronounced adhesive roofs, and at the economic tract was in parts with wooden lintel and partly also with wooden shingles dressed. Built in the second half of the 18th century, inside it had changes from the 50s. It was partly in bad condition. Upstairs it had a room with a classicist wall clock with an artistically executed case (early 19th century). Just like the parlour are the adjoining sleeping chambers panelled on wall and ceiling. House No.6 is a bit more modest as a single object as most of the remaining buildings within the core zone, yet it's an important part of the ensemble. As well as house no. 5, it is related to the opposite house No.3 and together they form the second bottleneck at the entrance to Schwarzenberg from the south (the effect of a quasi Zipper-like interlocking between the buildings No.5, No.3, No.6, No.2 and No.7 may be the reason for the each other's orientation opposite the street west- or east-facing houses).

Aim of retrofit

Renovation + Extension

The aim was to extend the existing living area and make it a comfortable home to the family of the owner and architect. In the front house - the former farmhouse – all intact components of the building should have been preserved. The installations of the 60th and 70th had to be removed. The important components had to be adapted in order to stick to the heritage assessments. Damaged or destroyed components had to be replaced. The wooden panelling should be kept. The airtightness and energy efficiency should have been improved in the most possible and useful way. The new owner wanted to use all the given volume and therefore he adapted the barn into a living area. His aim was to keep the structure of the building envelopes.

Was there any change of use?

The former barn has been converted into living area.

Lessons learned

Due to the preservation of the window situation (protection of the townscape), insulation was only possible to a limited extent - otherwise, due to very deep window reveals, the incidence of light and the quality of the view are lost - funnel windows. For this reason, attention was mainly paid to draught-free operation at the vapour barrier level. Therefore, the renovation is more or less "mono-material with wood or with wood fibre products" without foils (without blocking levels). The decisive factor is flow tightness in the connection joints and component transitions (wall/ceiling). The insulation thickness decision is therefore a mixture of considerations about the dew point and further drying behaviour.

Stakeholders Involvement

Architect
Thomas Mennel
Hof 6, Schwarzenberg

Conservation Consultant
Barbara Keiler
6900 Bregenz, Amtsplatz 1

Services Engineer
Planungsteam e-Plus
Gerbe 1135, 6863 Egg, austria

Tools used

Was the renovation process done following a specific methodology? No

Energy calculation energy certificate from 2007
Hygrothermal assessment non
Life Cycle Analysis (LCA) non

VN - newspaper supplement 11/2013 www.bauwelt.de Book „Alte Bausubstanz“ Bundesdenkmalamt Wien Book „Belebte Substanz, Umgebaute Bauernhäuser im Bregenzerwald“ Florian Aicher, Hermann Kaufmann

RETROFIT SOLUTIONS

External Walls

wood block wall

Block knitted wall 12-13cm, inside paneled, - supplemented by 2 layers of soft fibre - Wood wool insulation with laths, - wind sealing sheet - Rear ventilation and shingle formwork (for space reasons partly without rear ventilation) (contrary to the energy certificate only wood wool products were processed)

The intervention could be done underneeth the wooden shingles. Not to become to deep window- holes the architect did not take a much better (thicker) insulation.

Presentation of Thomas Mennel at "tri 2011"

U-value (pre-intervention) [W/m2K]: 1,2 W/m²K U-value (post-intervention) [W/m2K]: 0,6 W/m²K

More Details

Original wall build-up

Wood panelling - wooden panels:
20 mm

Wood - Block construction wall:
130 mm

Other - rear ventilation:
20 mm

Wood panelling - shingels:
20 mm

Retrofitted wall build-up

Wood panelling - the original wooden panels:
20mm

Insulation - 2 layers of soft fibre:
42 mm

Insulation - Wood wool insulation with laths:
30 mm

Air gap - wind sealing sheet:
2 mm

Wood - the original block construction wall:
130 mm

Other - rear ventilation:
20 mm

Wood panelling - Wooden shingels:
20 mm

Windows

Box windows front building

The old box windows had to be renewed but for the safety of the wall components the U-Values did just change slightly withe the new common glasses.

For the appearance of the building at the centre of Schwarzenberg the windows had to stay the same. The windows have two separate window elements. In summer it is possible to take away the front part of the window. The old frames were taken again.

Existing window U-value Glass [W/m2K]: 1,5 New window U-value Glass[W/m2K]: 1,5 Existing window U-value Frame [W/m2K]: 2,0 New window U-value Frame [W/m2K]: 2,0

More Details

Existing window type	Box-type window
Existing glazing type	Single
Existing shading type	Outer shutter
Approximate installation year	1870

New window type	Box-type window
New glazing type	Single
New shading type	Outer shutter
New window solar factor g [-]	0,75

Other interventions

ROOF

GROUND FLOOR

OTHER

MEASURES TO INCREASE AIRTIGHTNESS

ROOF

The renovation was the chance to renew the roof, becaus it was not leekproof anymore. It was in bad condition, had an ammonia smell in the barn and had to be completely renewed. The biggest change of the roof was the installation of a thermal solar system and a big glazed opening.

The saddle roof is part of the city centres ensemble and therefore it had to stay the dimension it had before.

U-value (pre-intervention) [W/m2K] 4 U-value (post-intervention) [W/m2K] 0,28

More Details

Original roof build-up

Tiles - The roof was tiled over the main building and the barn with Eternit tiles. It was in bad condition, had an ammonia smell in the barn and had to be completely renewed. :
30 mm

Other - visible rafters and beams:
200 mm

Retrofitted roof build-up

Shingles - shingels:
30 mm

Other - wood panels:
10 mm

GROUND FLOOR

The barn had no base plate before and with the extension of the main building this changed. The ground floor became an insulation from underneath/the basement.

The conservation did not change the material of the ground. in many parts of the existing living area, the ground was covered by linoleum. The new owner just used wooden boards.

U-value (pre-intervention) [W/m2K] 2,5 U-value (post-intervention) [W/m2K] 0,17

More Details

Original groundfloor build-up

Floor joists :
117 mm

Finish - wood flooring:
15 mm

Retrofitted groundfloor build-up

Floor joists - wooden beams:
150 mm

Other - dirt shield:
1 mm

Other - gypsum fiberboard:
20 mm

Insulation - softwood panel:
75 mm

Finish - wood flooring :
54 mm

OTHER

In addition to the front door on the street side, access to the house was also possible via the car park/rear entrance. This was otherwise used as a porch. For the lighting in the rear part of the house, parts of this this porch wer now fully glazed.

Although the appearance of this conservatory is very different from the original one, the benefits are the same.

rear entrance situation before the intervention, Copyright © Thomas Mennel

left part of the rear entrance after the intervention, Copyright © Thomas Mennel

right part of the poarch, Copyright © Thomas Mennel

MEASURES TO INCREASE AIRTIGHTNESS

The architect managed the airtightness with two layers of softwood panels without any foils or better without any serrender layers.

project presentation by Thomas Mennel at TRI 2011

HVAC

HEATING

DOMESTIC HOT WATER

HEATING

The old system was an oil heating system which did not fit to the new building anymore.

The owner didn't change the heating distribution system and just renewed the radiators with new but old looking radiators from Zehnder.

More Details

	New primary heating system	New secondary heating system
New system type	Boiler	Stove
Fuel	Biomass	Biomass
Distribuition system	Radiators	Air
Nominal power	kW	kW

DOMESTIC HOT WATER

A new thermal solar system was installed, which provides hot water for the two flats at least during two third of the year. If required the pellet boiler takes the rest.

The solar system is a roof integrated system.

More Details

	New DHW system
Type	RES
Hot_water_tank	Oui
With heat recovery	No

RENEWABLE ENERGY SYSTEMS

SolarThermal

Biomass

SolarThermal

The systems provides hot wate for the two families almost during three quarter of the year.

Roof-integrated collector solution with special modules between the rafters (this special solution was approved at the request of the monument office and the planning department) with attached shed glazing, analogous to the adjacent roof glazing for the lighting.

More Details

	SolarThermal System
Type	Flat collector
Collector area	20,0 m²

Biomass

A pellet boiler did replace the oil heating system.

The former farm house has an tiled stove which has no historical importance.

More Details

	Biomass System
Type
Storage size
Origin of biomass
Overall yearly production	kWh

Energy Efficiency

Energy Performance

Energy performance certificate: No
Voluntary certificates: No

Energy Use

Documents:

Berechnung der Norm-Heizlast nach EN 12831 --- Standard-Variante (ausführlich) -.pdf
Consumption_estimation_After: 73 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: NA
Consumption_estimation_Including_DHW: No

Costs

Financial Aspects

There are no cost aspects available.

Running Costs

Lifecycle cost
No