The project P4 (official title: EPA – Efficiency House Plus for Existing Buildings) demonstrates how it is possible to radically improve energy efficiency levels while at the same time significantly increasing user comfort in old buildings through suitable planning and building measures. A typical row of buildings from the 1930s was renovated to meet the Efficiency House Plus Standard as part of the German government’s ‘Zukunft Bau’ research initiative. The cubage and the essential, distinctive design elements of the existing structures were deliberately retained. The buildings contain a total of 10 residential units. The apartments on the ground floor have been developed to make them accessible for people with disabilities.
The existing fabric of the buildings was preserved to the greatest possible extent. Only the roof structure was removed and replaced with prefabricated wooden elements. This allowed extra living space to be added in the roof. The attic boards were reused during the renovation work. As few adhesive bonds were used as possible during the project to allow the structures to be dismantled cleanly into their constituent materials if necessary in future. The tried-and-tested building technology system was designed to be as simple as possible and was stripped down to contain only a minimal combination of easily obtainable components. The use of fossil fuels was avoided altogether – the buildings are exclusively supplied with energy from renewable solar and geothermal sources.
Werner Sobek, Stuttgart/Germany
2012 − 2013
2013 − 2016
Services by Werner Sobek
German Federal Ministry of Transport, Building and Urban Development
German Federal Institute for Research on Building, Urban Affairs and Spatial Development
Zooey Braun, Stuttgart/Germany