Sani60ies - Demonstration of minimally invasive thermal and energetic refurbishment of classic 1950s and 1960s apartment buildings

System development of a façade-integrated building component activation for "warm" refurbishments with high transfer potential to buildings of classic apartment complexes from the 1950s and 1960s. The system is being tested and further developed based on three building projects and demonstrated through broad application (over 200 flats).

Short Description

Starting point / motivation

The decarbonization of heating and hot water production in existing urban residential buildings should - for social and economic reasons - be pursued with minimal intervention in the housing stock and also - for reasons of efficiency in the operation of heat pumps - enable a reduction in the heating flow temperatures.

Contents and goals

The project "Sani60ies" addresses both these two challenges. It develops a system of façade-integrated component activation, which is installed between the former exterior of the existing wall and the newly applied full thermal insulation in the course of thermal renovation of existing buildings without interfering with the interior of the apartment units.

With this highly innovative system, a base load for the winter heat supply is achieved at low flow temperatures, while at the same time utilising the potential for energy flexibility. The coupled measure of thermal refurbishment and new external wall heating allows for a significant reduction of the flow temperature of the existing radiators, increasing their energy efficiency.

In addition to climate-friendly heating, the system offers climate-neutral cooling in summer.


Operationally, the system developed by the consortium will be tested on two smaller buildings before it is applied in a 1960s housing estate with over 200 flats. Heat flows are calculated and the effects on the interior of the façade-integrated component activation are dynamically simulated over the course of a year.

All three properties planned for implementation are owned by Sozialbau AG, Austria's largest non-profit property developer. The staggered implementation enables the optimisation of the system prior to its widespread application. In addition to energy and comfort monitoring, surveys of the residents will be conducted to measure subjective thermal comfort. The effectiveness of the system can thus be checked and ensured.

Expected results

It is the declared intention of the project to create a multipliable basis for a broad application of this minimally invasive system with the pilot application of the façade-integrated component activation and beyond the circle of the consortium.

Project Partners

Project management

Institute of Building Research & Innovation ZT GmbH

Project or cooperation partners

  • SOZIALBAU gemeinnützige Wohnungsaktiengesellschaft
  • Universität für Bodenkultur, Institut für Verfahrens- und Energietechnik (IVET)
  • Vasko+Partner Ingenieure GmbH

Contact Address

Institute of Building Research & Innovation ZT GmbH
Wipplingerstraße 23/3
A-1010 Vienna
Tel.: +43 (1) 5811 319 810