Minister Peter Hanke and City Councillor Hanel-Torsch visit a renovated residential building that sets new standards for sustainable renovation
Historic Gründerzeit Building Transformed into Energy-Efficient Residential Project
A historic apartment building in Vienna-Favoriten has been transformed into a showcase project for sustainable renovation.
The renovation of Fernkorngasse 41 combines innovative energy technologies, renewable energy systems and ecological building materials to demonstrate how existing urban buildings can be upgraded for climate-friendly living.
The project received €500,000 in funding from the Federal Ministry for Innovation, Mobility and Infrastructure (BMIMI) through the “Technologies and Innovations for the Climate-Neutral City (TIKS)” programme.
Shower Waste Water Heat Recovery Reduces Hot Water Energy Demand
A key innovation in the project is the installation of decentralised shower waste water heat recovery across all apartments.
By recovering heat from shower wastewater and reusing it for domestic hot water preparation, the system captures energy that would otherwise be lost down the drain.
In combination with the building’s high level of insulation, the technology reduces domestic hot water energy demand by approximately 30–40%.
The project demonstrates how waste water heat recovery can contribute to more energy-efficient apartment buildings, particularly in urban renovation projects where space and installation options are limited.
A Complete Energy Concept for Urban Renovation
The building renovation combines multiple sustainable technologies:
- Ecological insulation materials, including straw insulation and glass bead plaster
- Renewable geothermal energy
- Heat pumps for heating, cooling and hot water production
- Solar PV generation
- Shower waste water heat recovery
Together, these technologies create a fully renewable energy concept for the building.
Geothermal Energy Opens New Possibilities in Vienna
Another important element of the project is its innovative geothermal system.
Six deep boreholes combined with heat pumps provide fossil-free energy for heating, cooling and hot water.
Four of these boreholes were installed on public land — an approach rarely applied in Vienna — demonstrating new opportunities for renewable energy systems in densely built urban areas.
78% Reduction in Heating Energy Demand
The renovation significantly improved the building’s energy performance.
Measures included:
- Thermal renovation of street and courtyard façades
- Basement ceiling insulation
- Replacement of windows
- External solar shading
- Passive cooling through underfloor heating
As a result, the building’s heating energy demand was reduced by approximately 78%.
A Model for Future-Proof Renovation
The Fernkorngasse 41 project shows how historic buildings can be modernised without compromising their character.
By combining renewable energy, ecological materials and innovative technologies such as shower waste water heat recovery, the project provides a blueprint for sustainable renovation in urban environments.
It demonstrates that existing housing stock can become more energy-efficient, comfortable and future-ready while supporting climate-neutral building goals.
Link to original article: https://www.ots.at/presseaussendung/OTS_20260622_OTS0054/innovative-altbausanierung-in-wien-favoriten-gruenderzeithaus-wird-zum-vorzeigeprojekt-fuer-klimafittes-wohnen
Questions & Contact
Federal Ministry for Innovation, Mobility and Infrastructure (BMIMI)
Carina Novy
Telephone: +43 1 711 62-65 8010
Email: carina.novy@bmimi.gv.at
Website: https://bmimi.gv.at