VELUX Sunlight House

Sunlight House is Austria’s first carbon-neutral single-family house. Nestled in a wooded, mountainous region, the home’s sloping roof & other exciting architectural elements take full advantage of the sun to ensure maximum daylight and solar energy. 

The home’s design was the result of a competition between nine up-and-coming Austrian architects, and the winner was Hein-Troy Architekten. VELUX Austria is monitoring the project along with our partners at Danube University Krems and the Institute for Healthy and Ecological Building (IBO). Sunlighthouse is the recipient of the Austrian State Prize for Environment and Energy Technologies. 

In it are installed various types of VELUX roof windows. The immediate energy balance is calculated as being current incident solar energy minus the heat loss through the window. If the energy balance is greater than zero, the window is adding energy to the building. The holistic concept of the house has already been awarded the Austrian State Prize for Environment and Energy Technology.

Taking an active part in developing sustainable buildings, the VELUX Group has launched the project Model Home 2020. Six full-scale experimental demo-houses are being built in five European countries from 2008 to 2011. Sunlighthouse, near Vienna, will be the third demo-house to realise the VELUX vision of carbon-neutral buildings that combine efficient energy design with a high degree of habitability and minimum climate impact. The Austrian house is designed to produce so much renewable energy with photovoltaics and solar heat that it will cancel out all CO2 emissions arising from its operation and construction – including production, transport and future disposal - within the next 30 years.

Numerous guests took part in the ceremony. Among them the Danish Ambassador to Austria, S.E. Hugo Østergaard-Andersen, who praised the exemplary project and emphasised the leading role of the VELUX Group in sustainable buildings. Together with Michael Walter, General Manager of VELUX Austria, Josef Schmidl-Haberleitner, mayor of Pressbaum, the architect Juri Troy and the General Managers of VELUX Hungary and VELUX Slovenia, Mads K. Rasmussen and Vojko Golmajer, he wielded the spade for the official ground breaking of Sunlighthouse. Furthermore, as a symbol of the ecological footprint of this unique building, the guests of honour left their individual footprints in a special concrete slab.

One experiment is better than a thousand expert views

More than half a century ago, VELUX founder Villum Kann Rasmussen made the statement that “one experiment is better than a thousand expert views”. This principle is just as valid today and will be applied to the six houses of the Model Home 2020 project. The objective is to gain information and experience on how future buildings in different regions with different climates, cultures and architectural conditions, can be both climate-neutral and comfortable.

“For the Austrian project we have deliberately chosen a plot that is typical of the sometimes difficult conditions of mountainous regions,” explains VELUX Austria General Manager Michael Walter. “The idea is to demonstrate that even under these challenging conditions it is possible to build sustainable constructions by balancing energy, environment and indoor climate with plenty of daylight and fresh air.”
Exceptional levels of daylight

Thanks to the interdisciplinary cooperation between VELUX Austria, the Danube University Krems and the Austrian Institute for Building physics (IBO), a tailor-made, scientifically sound concept has been created together with the architect. Confronted with the high degree of shadow on this construction site, the architect Hein-Troy had to come up with some creative ideas for getting more daylight into the house. A very sophisticated window configuration - of the roof windows as well as the vertical elements – will provide the different levels of Sunlighthouse with plenty of daylight and ensure a positive effect on the health and well-being of the residents. 


17 photos and 4 drawings

Building Activity