GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Musikschule Velden

Bäckerteichstraße 1

9220

Velden am Wörthersee, Austria

Architect

Arch + more ZT GmbH

Dr. Karl-Renner-Weg 14, A-9220 Velden am Wörthersee

Owner

Marktgemeinde Velden am Wörther See

9200 Velden, Seecorso 2

User

Contact Details

Susanne Kuchar

e7 energy innovation & engineering

susanne.kuchar@e-sieben.at

+43 1 907 80 26 - 67

Other Information

Restoration of a former fire station and transformation into a music school including a comprehensive thermal-energetic renovation

GENERAL INFORMATION RENOVATION PROCESS RETROFIT SOLUTIONS EVALUATION

Energy performance

27,24 kWh/m2.y

Climate Zone Dfb

Altitude 455 m a.s.l.

HDD 3753

CDD 100

Protection level Listed

Conservation Area:
No

Level of Protection:
DMSG § 2a

Building age 1900-1944

Year of last renovation:
2015

Year of previous renovation:
0

Building use Educational/Research

Secondary use:
NA

Building occupancy:
Discontinuous occupancy (i.e. holiday home)

Number of occupants/users:
0

Building area Net floor area [m²]: 680,0

Building typology:
Detached house

Number of floors:
5

Basement yes/no:
Yes

Number of heated floors:
4

Gross floor area [m²]:
1099,0

Thermal envelope area [m²]:
1732,0

Volume [m³]:
3062,0

NFA calculation method:
NGF (de)

Construction type

Brick masonry wall

External finish:
Rendered

Internal finish:
Plastered (on substructure)

Roof type:
Pitched roof

+ MORE - LESS

View of main street fassade (blende16/ARCH+MORE)

View of main entrance from Franz Baumgartner Platz (blende16/ARCH+MORE)

View of teachers entrance (blende16/ARCH+MORE)

Lecture hall, the former vehicle hall (blende16/ARCH+MORE)

Barrier-free access by elevator in the former hose tower (blende16/ARCH+MORE)

View from main street (blende16/ARCH+MORE)

RENOVATION PROCESS

Architecture

BUILDING DESCRIPTION

The former fire station is a listed building, which was built in 1926 by architect Franz Baumgartner in the style of the architecture at the lake Wörther See. It is now used as a music school. The building is characterised by its strongly articulated gates on the main street façade. The large roof area is broken up by an enormous front gable. The building comprises two full floors, an attic, a partial basement and a turret room. The market town of Velden am Wörthersee implemented a comprehensive thermal-energetic renovation of the building. This renovation was carried out within the framework of the demonstration programme “Mustersanierung”. The innovative measures and the project documentation were funded by the Austrian Climate and Energy Fund. The building achieved the klimaaktiv GOLD standard, an Austrian rating system for the sustainability of buildings.

Urban context

The building is centrally located in the town of Velden in the area of the educational campus near the lake Wörther See and can be accessed is from the square Franz-Baumgartner-Platz. The building consists of two parts, the listed one that was the subject of the renovation described here and an annex that houses a medical practice.

State of repair

Conditions of the envelope

Since its erection in the 1920s, the existing building has not undergone a general refurbishment.

Description of pre-intervention building services

Heat supply: Central, default value for output (102 kW), district heating, Secondary circuit, no storage. Distribution lines, risers, and connecting lines: Lengths all-inclusive, not conditioned, 1/3 insulated, fittings uninsulated. Distribution: Individual room control with thermostatic valves, individual heat consumption calculation, radiators (70 °C / 55 °C).

HERITAGE SIGNIFICANCE

ELEMENTS WORTHY OF PRESERVATION

The box-type windows, the façade and (partly) the standing construction were worthy of preservation, as well as ceilings, stairs, floors and the interior decoration (wooden ceiling, windows and doors, terrazzo floor). - The wooden ceiling was removed at the edge in order to guide the interior insulation upwards without thermal bridges. The ceiling was then shortened and fitted. - The profiles of the windows were partially copied in order to achieve the technical standard. - For the terrazzo, an optical compromise (width of the border reduced) was necessary due to the interior insulation. - The ventilation was integrated into the historic wooden ceilings (only existing openings were used). - The ceiling doubling for room acoustic separation was carried out in a way that was clearly readable in terms of design.

Heritage Value Assesment

The building is a listed building and, due to its status as a Wörthersee architectural jewel, was supervised by the Federal Office for the Protection of Monuments during the renovation. The existing building was inspected in an on-site inspection, during which the planning principles and requirements of monument protection were discussed.

Aim of retrofit

Renovation + Extension

The aim of the renovation was to ensure that the building meets the contemporary standards of a music school and can be used multifunctionally for various events, seminars and associations. As an e5 community (program for energy-efficient communities in Austria), Velden has a great awareness of sustainability. As a result, the planners were asked from the beginning to think comprehensively about sustainability and to optimize energy efficiency. The logical conclusion was to take part in the funding program "Mustersanierung" (model renovation). The financial support was facilitating but not decisive. The objectives of the renovation were the ecological use of materials (80 % eco-label products), reaching the klimaaktiv Gold certification and a chemical management ("healthy learning spaces for our children").

Was there any change of use?

The building was a former fire station and is now used as a music school. The fire department had moved out in the 2000s and it was the endeavor of the market community of Velden am Wörther See as owner to revitalize the building. Therfore, excursions and workshops were organized with cultural associations and educational institutions in order to define common goals. Due to the shortage of space for the educational institutions, it was then decided, together with the cultural institutions, to comprehensively renovate the building as part of the Bildungscampus Velden for the music school, whereby the ground floor (former vehicle hall) and the historic meeting room on the upper floor were converted into multifunctional rooms with equipment for all cultural institutions. This dual use of the classrooms required an increased effort in acoustic separation and the highest level of room acoustics (also in connection with the protection of historical monuments, as no acoustic cladding or additional ventilation openings in historical elements were possible from this side).

Lessons learned

There were many constructive discussions with the future users during the planning phase. Close cooperation within the planning team and with the users was essential for the success of the project. Close cooperation was also required with the Federal Monuments Authority with regard to the planned measures and materials, especially in the areas of interior insulation and optics. In addition, the reduction of thermal bridges and compliance with fire protection regulations were a complex part of the planning process. It is also important to involve the future facility managers of the building in the project already during the planning phase. This is often problematic due to a lack of personnel, especially in public buildings.

Stakeholders Involvement

Public sector
Market town of Velden am Wörther See
Seecorso 2, A-9021 Klagenfurt/Wörthersee

Private Sector
Director of music school
Bäckerteichstraße 1, A-9220 Velden am Wörthersee

Architect
Arch + more ZT GmbH
Dr. Karl-Renner-Weg 14, A-9220 Velden am Wörthersee

Conservation Consultant
Federal Monuments Authority Austria - Department for Carinthia
Alter Platz 30, A-9020 Klagenfurt am Wörthersee

Energy Consultant
IPJ Ingenieurbüro P. Jung GmbH
Luftbadgasse 3/8, A-1060 Wien-Mariahilf

Tools used

Was the renovation process done following a specific methodology? No

Energy calculation Calculation according to energy performance certificate for non-residential buildings
Other Blower-door test

Energy certificate before renovaiton (IPJ Ingenieurbüro) Energy certificate after renovaiton (IPJ Ingenieurbüro) Blower door test (AEO) Article in "Kleine Zeitung" (E. Hirtenfelder) Article in "Wirtschaftsblatt" (M. Manner) Measurement report indoor air (IBO) Building characteristics in summer (IPJ Ingenieurbüro) Certificate klimaaktiv GOLD (BMLFUW)

RETROFIT SOLUTIONS

External Walls

Außenwand 45

The façade was restored on the outside and adapted to the original colour scheme for reasons of monument protection. On the inside, the thermal renovation was executed with an internal insulation in the form of 8 cm calcium silicate boards, whereby care had to be taken that the existing construction would not suffer any damage in the long term.

The adaptation of the façade to its original condition and the choice of thin insulating panels on the inside of the exterior walls ensured to preserve the original character of the building. Also, Calcium silicate boards were selected as insulation material with regards to protection of historical monuments, ecology and summer overheating protection.

U-value (pre-intervention) [W/m2K]: 1,18 W/m²K U-value (post-intervention) [W/m2K]: 0,38 W/m²K

More Details

Original wall build-up

Plaster - Plaster mortar (lime cement):
20 mm

Brick - Solid brick:
400 mm

Plaster - Plaster mortar (lime cement):
20 mm

Retrofitted wall build-up

Plaster - Plaster mortar (lime cement):
20mm

Brick - Solid brick:
400 mm

Plaster - Plaster mortar (lime cement):
20 mm

Insulation - Multipor-ID (interior insulation):
80 mm

Plaster - Filling:
2 mm

Windows

Gate windows

Box-type windows

Gate windows

The window openings could not be changed. The window joints (also the structural joints) of the historic windows were resealed and window seals were milled in. Due to this an air tightness 0.8 1/h could be achieved. Inner wings were replaced with insulating glass. The outer color of the windows was changed to the original one. On the inside at the level of the internal insulation, thermal insulation glazing was installed.

The U-values could only be approximated, since the windows are historic box-type windows that were reworked (single glazing on the outside, inner wing with doulbe glazing, with sealing plane). U-value existing window (frame and glas) about 2,5 W/m²k. U-value new window (frame and glas) about 0,82 W/m²k.

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

More Details

Existing window type	Box-type window
Existing glazing type	Single
Existing shading type	NA
Approximate installation year	1926

New window type	Box-type window
New glazing type	Double
New shading type	NA
New window solar factor g [-]	0,67

Box-type windows

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

More Details

Existing window type	Box-type window
Existing glazing type	Single
Existing shading type	NA
Approximate installation year	1926

New window type	Box-type window
New glazing type	Double
New shading type	NA
New window solar factor g [-]	0,54

Other interventions

ROOF

GROUND FLOOR

MEASURES TO INCREASE AIRTIGHTNESS

ROOF

The existing wooden construction doubled to the inside and in order to guarantee the thermal renovation, additional insulation with cellulose was installed on the inside. Furthermore, the existing roof covering was renewed.

The appearance of the roof was kept, but the colour changed to the original. Cellulose was chosen as a insulation material with regards to protection of historical monuments, ecology and summer overheating protection.

U-value (pre-intervention) [W/m2K] 2,092 U-value (post-intervention) [W/m2K] 0,093

More Details

Original roof build-up

Other - Cement board (Eternit):
5 mm

Other - Wooden battens:
20 mm

Other - Wooden beams:
160 mm

Retrofitted roof build-up

Other - Cement board (Eternit):
5 mm

Other - Sealing (diffusion open):
1 mm

Other - Wooden battens and beams:
219 mm

Other - TJI beams with cellulose fibre insulation:
300 mm

Other - Vapour control layer:
1 mm

Other - Planking:
24 mm

Other - Plaster board:
25 mm

GROUND FLOOR

The existing floor in the event hall without basement and the floor of the existing basement were completely removed and rebuilt with XPS (with Austrian eco-label).

There were no issues with conservation regarding the ground floor.

U-value (pre-intervention) [W/m2K] 4 U-value (post-intervention) [W/m2K] 0,586

More Details

Original groundfloor build-up

Concrete slab - Concrete B160:
60 mm

Retrofitted groundfloor build-up

Concrete slab - Concrete (B160):
120 mm

Other - Bituminous sealing:
1 mm

Insulation - XPS:
40 mm

Other - Dry screed Laying slab:
20 mm

Finish - Tiles:
10 mm

MEASURES TO INCREASE AIRTIGHTNESS

Window joints (including component joints) of the historic windows were resealed and window seals were milled in, and interior sashes were replaced with insulated glass. A possible backflow of the interior insulation was taken into account by completely removing old layers of paint and applying new layers with notched trowel, so that a backflow is kept to a minimum.

Sealed historic window (blende16/ARCH+MORE)

Detail of sealed historic window (ARCH+MORE)

Airtightness (pre-intervention) [ach@50Pa] 0 Airtightness (post-intervention) [ach@50Pa] 0,78

HVAC

HEATING

VENTILATION

HEATING

It was the conversion to 100% renewable district heating, for which proof of delivery was requested. The heat delivery system consists of underfloor heating on the ground floor in the area where the floor structure was redone, and radiators on the upper floors. In addition, a comfort ventilation system (2 units, 1x for the hall and 1x for the classrooms) with heat recovery was implemented.

For the comfort ventilation system, the fresh air intake and exhaust air discharge was carried out via the historic chimneys, as this was not possible on the facade.

Heating system documentation (IPJ Ingenieurbüro)

More Details

	New primary heating system
New system type	District heating
Fuel	Industrial heat, biomass and gas
Distribuition system	Radiating floor, radiators and air
Nominal power	42 kW

VENTILATION

The building was equipped with two central and one decentralized comfort ventilation system. One unit is located in the attic room above the theory room and supplies the classrooms and the theory room on the 1st floor as well as the classrooms on the top floor. The second unit was installed in the existing technical room and supplies the event hall, the assembly hall and the basement. The decentralised ventilation unit operates the sanitary facilities and is located on its flat roof. Outside air and exhaust air are led over the existing chimneys. Linen sacks on the ceilings of the classrooms ensure an extremely gentle air supply. Heat recovery: Room air technology with variable air volume flow, air exchange rate for air tightness test (n50) = 0.8 1/h, additional air exchange rate (nx) = 0.056 1/h, no heating function, no cooling function, own heat recovery system, degree of heat supply = 80 %, own geothermal heat exchanger, degree of utilization EWT = 20 %. Type of ventilation: no night ventilation, bypass system available, no humidifier, limitation of maximum air volume flow, maximum air volume flow = 2970 m3/h.

The fresh air intake and exhaust air discharge was carried out via the historic chimneys, as this was not possible on the historic facade.

Linen sacks for extremely gentle air supply in the top right of the picture (blende16/ARCH+MORE)

Linen sacks for extremely gentle air supply in the top left of the picture (blende16/ARCH+MORE)

More Details

Original roof build-up	New ventilation system
Type ventilation system	2 centralised and 1 decentraliced systems
Type flow regime	Overflow
Heat recovery	Yes
Humitidy recovery	No
Nominal power	No information kW
Electric power	kW
Control system	Air exchange takes place according to air tightness test (n50) = 0.8 1/h

RENEWABLE ENERGY SYSTEMS

Photovoltaic

The new PV is situated on a part of the buiding with a flat roof. The average yield of the PV system is about 10,000 kWh per year, of which about 40% is consumed in the renovated building and the remaining electricity is passed on to the neighboring doctor's office.

The PV was installed on the part of the building, which is not under conservation.

More Details

	Photovoltaic System
Type	NA
Collector area	80,0 m²
Total nominal power	10,0 kW
Overall yearly production	9600,0 kWh

Energy Efficiency

Energy Performance

Energy performance certificate: Energy certificates for non-residential buildings were compiled before and after the renovation.
Voluntary certificates: The klimaactive gold award for competence in climate protection for the renovation of the music school Velden states that his building combines highest energetic and ecological quality with professional execution and thus meets the building standard of klinaaktiv gold.

Energy Use

Heating
Consumption_estimation_Calculation_method: Calculation according to energy certificate for site climate
Consumption_estimation_Before: 418,05 kWh/m2.y
Consumption_estimation_After: 27,24 kWh/m2.y

Primary Energy
Consumption_estimation_Calculation_method: Calculation according to energy certificate for site climate
Consumption_estimation_Including_DHW: Yes
Consumption_estimation_Before: 856,2 kWh/m2.y
Consumption_estimation_After: 247,4 kWh/m2.y

Measured Parameters

Internal Climate
Type_of_monitoring: Continuous
Description: Two classrooms were monitored according to their climate (temperature) during summer.

External Climate
Type_of_monitoring: Continuous

Internal Climate

Temperature

There is an ongoing exchange with the users in which the building is optimized, also the temperature. This is especially necessary in the case of a high-quality refurbishment, as not everything can work at the start of operation and thus an ongoing evaluation is necessary to achieve user satisfaction.

Indoor Air Quality

There were many constructive discussions with the future users of the music school during the planning phase regarding user comfort. Especially the resulting air supply via air bags works very well. The feedback from the users, especially regarding ventilation and sound insulation, is very positive.

Daylight

The window openings could not be changed, therfore, the lighting system inside was designed to be daylight-dependent.

Acoustic Comfort

Since the building is used as a music school , sound decoupling between classrooms and room acoustics through the installation of individual elements (additional Plexiglas suspension, Ecophon tw. on walls) were important.

Costs

Financial Aspects

Investment costs applied for: € 1,460,826. Environmentally relevant costs: € 937,001. Funding basis: € 661,584. Subsidies: € 283,858.

Investment Costs

Total investment costs
€ 1.460.826,00 (total)

Running Costs

Lifecycle cost
No

Environment

Greenhouse Gas Emissions

Methodology_used: Calculation according to energy certificate for site climate
emissions_at_use_stage_before_intervention: NA NA
emissions_at_use_stage_after_intervention: 31.40 kg/m²y per m2
emissions_before_use: 48,.40 kg/m²y