Family tests C02-neutral VELUX Sunlighthouse


Now comes the tough practical trial: for a whole year Yasmin and Ludwig Dorfstetter and their two children will be testing Sunlighthouse in practice.

So far the VELUX Sunlighthouse has enthralled energy experts and designers, winning multiple prestigious awards. Now comes the tough practical trial: for a whole year Yasmin and Ludwig Dorfstetter and their two children will be testing whether it is actually possible to combine energy-efficient home-building with minimal CO2 emissions and a healthy, comfortable living environment.

This active house, challengingly situated on a slope and in partial shade, is fully surrendering itself to everyday family life. Every detail will be scientifically evaluated, and the personal Internet reports of the family about their experiences will be eagerly awaited.

No shortage of volunteers

The Sunlighthouse Family Search produced a frantic rush to the VELUX website. More than a hundred families from all over Austria did not want to miss out on the unique opportunity to help shape the future of green home-building and living. Not to mention a whole year living rent-free in an architecturally appealing and ecologically unique dream house with a panoramic view. It was no easy task for the jury to choose from the large number of motivated and likeable applicants.

In the end, though, the members of the jury, consisting of VELUX representatives, communications experts and psychologists, reached agreement and declared the Dorfstetter family the clear winner of this unique experiment.

Family with know-how and a spirit of adventure

Yasmin and Ludwig Dorfstetter had far more going for them than just their warm personalities, spirit of adventure and enthusiasm for the project. From their professional lives, both bring valuable knowledge of the field of ecology to the project:

Ludwig Dorfstetter (31), from Lower Austria, works for Austrian Federal Forests. As a scientific employee of the Climate Protection Research Collaboration, Yasmin Dorfstetter (29), born in the Allgäu Alps, is just the person to subject the VELUX Sunlighthouse to a thorough practical trial. "Sustainable management of natural resources has been a big part of our professional lives for a long time. So we're excited that this experiment also gives us an opportunity to help shape the future of ecological home-building and living in our private lives."

In order to do that, the couple, together with their children, Johann (2) and Alfred (4), are making the move from Salzburg to Lower Austria. They will be able to check out for themselves whether combing the concepts of the active house, energy efficiency, environmental conservation and healthy indoor climate will prove successful in practice.

The findings from this project will permanently change the ecological view on home-building and the environment. The family will not be alone in the one-year experiment. Numerous experts from the most diverse fields will accompany and support them on their way.

Diary and scientific monitoring

The Sunlighthouse in Pressbaum is part of the Europe-wide VELUX initiative Model Home 2020, demonstrating how energy-efficient home-building can be combined with minimal CO2 emissions and a healthy, comfortable living environment.

"We're curious about how it will feel on an everyday basis and will be reporting continually via the Internet in order to exchange information with interested home-builders and families," enthuses Yasmin Dorfstetter. Her husband adds, "In the next 12 months that we're in the Sunlighthouse, the specialists from the VELUX Group will be collecting practical data on energy consumption, indoor climate and comfort in the house. So we will be able to help further refine and improve the unique concept of the active house."

The first CO2-neutral single-family home in Austria

The VELUX Sunlighthouse was developed in close collaboration with HEIN-TROY Architekten, Danube University Krems and the Austrian Institute for Healthy and Ecological Building (IBO). Opened in October last year, it has so far enthralled energy experts, architects and designers, leading to awards such as the Austrian State Prize for Environment and Energy Technologies and the renowned Vorarlberg Timber Construction Award.

In respect of the active house principle, the Sunlighthouse embodies a holistic view; it is not just the energy for heating that has been given prominence, but low overall energy consumption, the use of environment-friendly building materials and a healthy indoor climate with lots of daylight and fresh air. The energy needed to run the house is produced solely from renewable energy sources.

The aim has been to produce not just Austria's first house that is fully CO2-neutral in construction and operation, but also a "plus-energy house" that continually produces more energy than it consumes.

In order to achieve this aim, every conceivable opportunity has been exploited: a brine-water heat pump, thermal solar collectors, photovoltaic solar cells, intelligent control of window ventilation, high-efficiency electrical devices, recycled building materials and renewable raw materials – the list of features is really comprehensive.

The optimal use of daylight gave the house its name: the window area is more than 50% of the living area, and thus five times higher than the minimum requirement of the building regulations.

The high level of daylight underlines the objective of assigning prime importance to the residents of this healthy house: numerous studies demonstrate the positive effect of natural light on our health.

Photo caption: Michael Walter, VELUX Österreich GmbH, and Deputy of the state parliament Wilibald Eigner hand over traditional bread and salt to Ludwig and Yasmin Dorfstetter.

About Model Home 2020

Model Home 2020 is an experiment launched by the VELUX Group as part of our strategy to take an active part in developing sustainable buildings for the future. It is our vision of how future buildings can be both climate-neutral and comfortable and attractive places to live in through daylight and fresh air.

The project is in full accordance with the next generation of design principles frequently referred to as "active house" ( The objective is to achieve a balance between energy efficiency and optimal indoor climate with a building that dynamically adjusts to its surroundings and yet is climate neutral.

Model Home 2020 comprises six demonstration projects. The two experiments in Denmark were built in a partnership between the VELUX Group and VELFAC. Each of the Model Home projects was implemented in close cooperation with local and regional partners, suppliers, architects, engineers and researchers.

In the VELUX Group, we believe that one experiment is better than a thousand expert views. Each building must reflect and respond to the different climatic, cultural and architectural conditions of the countries in which they are built. The houses will be open to the public for 6-12 months after completion and then sold. Each house will be monitored during occupancy to learn how the experiments turn out in real-life conditions.

The houses in Denmark – Home for Life in Aarhus and Green Lighthouse in Copenhagen – have been in use for a year, those in Germany and Austria opened in the autumn of 2010, and those in the UK and France followed in 2011.