PASSIVe house renovation, Makartstrasse, Linz

Modernization of a multistorey block of flats with 50 units (built in 1957/58). Renovation up to passive house standard.

Content Description





The thermally consistent redevelopment of old buildings can be seen as the most important contribution to an effective reduction of CO2 emissions. But it also provides the opportunity to enhance the energetic standard and therewith the comfort of these building. This project was the first redevelopment of a multifamily residence on passive house standard and that is why it should be considered as an ideal example.


The discovery of economically possible cost reductions and the implementation of the large- volume buildings in Linz based on passive house standard as a pilot project was a big step within the lasting building redevelopment industry.

This project includes all aspects of an effective concept of redevelopment in consideration of forward- looking methods of redevelopment. These methods lead to an at most saving of energy while the quality, usability and functionality are increased at the same time.


With the first redevelopment of a multifamily residence based on passive house standard in Austria all efforts have been made to enhance air quality, comfort and usability with the energy demand decreasing even of existing buildings where this has not been achieved before.

The aim of this project was to state an example for other old buildings.

  • First redevelopment of an old building based on passive house standard
  • Optimised ventilation and house automatic concept in order to obtain best air quality
  • Ecological refurbishment with renewable raw materials
  • Reasonable use of prefabricated materials
  • Refurbishment without disturbance of residents


  • Alternative project outline based on passive house standard
  • Calculation of possible constructions with PHPP
  • Comparison and analysis of different ventilation concepts
  • Examination of different decentral hot water conditioning
  • Development of prefabricated parts of the façade with built-in windows and a duct system for controlled ventilation of the housing space
  • Use of solar comb facades for redevelopment of old buildings

Modernisation of a multi- storey building with 50 accomodation units

Because of the prefabricated and ventilated GAP solar façade, an increased insulation of the ceiling on the roof and in the basement, an enlargement of existing balconies with parapet insulation, glazing with passive house windows with integrated sun protection, new roof covering and a controlled ventilation of the housing space with single room ventilators, the building (constructed in 1957/58) meets the requirements of a passive house.

Modern and future- orientated design of "old property".

Enhancement of quality of living conditions is possible because of an increase of sound insulation and good ventilation through high quality single room ventilation even with closed windows.

Multiuse of existing balconies is possible, because of an enlargement and enclosure built with thermally insulated parapet and side frame.The open spaces were closed with passive house windows and fixed glazing panels. A qualitative use of the balconies was not possible so far, because of the immense contamination and noise exposure due to the location of the building close to the highly frequented Makartstrasse. The total useable living area was increased from 2.755,68 m² to 3.106,11 m² thanks to the enclosure of the balconies.

Findings/Evaluation of heat consumption after the first period of heating

  • Energy figure reduction of room temperature from 179kWh/ma to 13,3 kWh/ma (with a practically reached air density n50<1,30 1/h)
  • Saving of 446.800 kWh/a - comes to factor <10
  • Reduction of CO2 emissions from approx. 160.000 kg/a to 13.000 kg/a
  • Additional costs to achieve passive house standard of approx. 27%
  • Additional costs for passive house and ecological actions in total approx. 30%

Information of the tenants/Feedback

During the phase of planning the tenants were informed about the planned passive house refurbishment through organised meetings. As there has not been a similar project in Austria before, people were concerned whether such a refurbishment project can be successful at all. Thanks to presentations and clearing discussions we reached the acceptance of the tenants.

Shortly before refurbishment work was finished there was another meeting with the tenants, where the feedback about achievements so far was very positive. The way of living in a passive house was explained to them again and people had the opportunity to exchange experiences.

Finally GIWOG received the certificate of BMVIT from Mr. Zillner (Dipl.-Ing) at the final celebrations on the 14th of September 2006. During this event the tenants took the opportunity to thank the construction management of GIWOG for the smooth construction sequence.

Thanks to the implementing of the ventilation system a decrease of heating costs as well as the abatement of a tenant ´s dust allergy were noticed.

"Living has become worth living again."


The final report for this project comes to the conclusion that the refurbishment of the social housing based on passive house standard leads to an immense improvement of the quality standard.

That is why the tenant ´s benefit up to 100% from the saving of heating costs between 80 and 90%.

During this project a promotion for the refurbishment based on the passive house concept was newly implemented through OÖ WBF. It is because of this promotion in connection with the rent regulation of WGG that the extra costs of this ideal refurbishment were held fairly low, so that there were no additional monthly charges for the tenants, also due to the saved maintenance provision in connection with the additional support of BMVIT.

Project Partners

Project management

Bmst. Ing. Alfred Willensdorfer
GIWOG Gemeinnützige Industrie-Wohnungs-AG

Project or cooperation partner

  • Architekturbüro ARCH+MORE, Puchenau
    Arch.DI Ingrid Domenig-Meisinger
  • Planungsteam E-Plus, Egg
    DI Bernd Krauß
  • gap-solar GmbH, Perg
    DI Mag. Johann Aschauer
  • LANG consulting, Wien
    Ing. Günter Lang


GIWOG Gemeinnützige Industrie-Wohnungs-AG
Bmst. Ing. Alfred Willensdorfer
Welser Straße 41, A-4060 Leonding
Tel.: +43 (50) 8888 0
Fax: +43 (50) 8888 197