This housing complex was built to meet the passive house standard. The main focus was to offer a variety of common spaces (like service areas, a nursery, and student and senior housing) in a central location and to have a lot of open spaces. The description that follows describes the multi-family section of the complex.
This newly built housing complex is comprised of approximately 21,000 m² net floor area and is the largest example of the collected NZEBs. The multi-family house is built with a thermal building envelope that meets the passive house requirements, including triple glazed windows. The complex is heated by a district heating system, while the domestic hot water (DHW) demand is mainly covered by a 700 m² solar thermal collector field on the roof. Part of the energy concept is a mechanical ventilation system which has a 75% heat recovery. The total final energy use for heating, hot water and ventilation amounts to 30.1 kWh/m².year and includes a 52% renewable energy contribution. It undercuts the current Austrian energy performance requirements by 43%. The applied architectural approach using a combination of common spaces and a swimming pool on the top floor, together with the infrastructure and equipment, results in the residents being highly satisfied with the building.
The building costs were 57 million € for the entire estate which can be recalculated to about 2,700 €/m² of which were partly subsidised by the Styrian government.
Net floor area: 21,000 m²
The house consists of a massive construction with insulated brick walls. The roof and the cellar ceiling are made of reinforced concrete, the windows have triple glazing.
Building envelope U-values:
- Wall: 0.18 W/m².K
- Window: 0.8 W/m².K
- Roof/ceiling to the attic: 0.11 W/m².K
- Cellar ceiling/ground slab: 0.11 W/m².K
Building service systems
The house is heated by district heating. It has a mechanical ventilation system with a 75% heat recovery. The demand of hot water is partially covered by 700 m² solar thermal panels on the roof.
Renewable energy systems
Solar thermal panels (700 m²) are used for heating the hot water and as support for heating. A heat pump is used for preheating the incoming air of the mechanical ventilation system.
Building Energy Performance
Final energy use:
Monitored in year:
incl. in heating
Electrical appliances (household electricity)
Primary energy use:
Primary energy factor of district heating: 1.52
Renewable energy contribution ratio:
About 52% of the total final energy
Award for Architecture and Sustainability