The Green House Competition has been launched to find people to live in and assess the Larch and Lime Houses at the former steel works at Ebbw Vale in South Wales, designed by bere:architects’ and built by United Welsh under a competition administered by the Building Research Establishment Wales. 

Both are certified Passivhaus houses with the Larch house being zero carbon (code 6). The competition winners are expected to enjoy extremely low energy bills, high levels of thermal comfort and high quality air even when windows are closed in winter, with low internal CO2 levels. The competition is open to anyone living in the Blaenau Gwent area and the winners will live rent free for 12 months.

The competition will gather feedback from the residents as to what it is like to live in some of the first low cost, certified Passivhaus social housing in the UK, and the information gathered from this study will feed into the two year Technology Strategy Board funded Building Performance Evaluation studies, and will influence Welsh Government decisions about future social house design in Wales.

Richard Mann, Head of Development for the UWHA says, “These are groundbreaking buildings. This unique competition will deliver an environmental monitoring project which will help mould the future of social housing in the UK. Fuel bills can be a big financial drain for social housing tenants, so we want to make sure our homes are as energy efficient as possible.”

Both houses are undergoing in-depth remote monitoring and evaluation as part of Technology Strategy Board funded studies to ascertain whether the houses are actually performing as designed. This will ultimately produce lessons from the innovative techniques used in building these homes and these lessons will be shared and used in future housing projects. Although the monitoring that has already been undertaken indicates that the houses are performing exceptionally well, the housing association and the architects will be very keen to hear and evaluate the feedback from those actually living in the houses day-to-day as their year in residence progresses.

Justin Bere, director of bere:architects says: “After a year in which the houses have been open for many hundreds of people to visit them and experience what it feels like to be inside a passivhaus, we are delighted that United Welsh are now moving on to the next phase which is to give two families the opportunity to live in them and test them out. This will be an important part of the Technology Strategy Board funded Building Performance Evaluation study. This started with monitoring the buildings without any internal heat gains from occupants and appliances and now it will be very interesting to see the impact that internal heat gains and occupant behaviour have on the performance of the building. This is important and exciting research work and we are delighted that United Welsh, the Welsh School of Architecture, and Cambridge Architectural Research are all such enthusiastic partners in this work.”

Further information about the competition can be found at

A Guardian piece and Justin's response to the comments can be found at