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In Germany, there are hardly any new buildings planned. Can an old house become an “Efficiency House”?



It is estimated that a third of the energy Germany consumes goes into heating and cooling buildings. Amazingly, households use roughly the same amount of energy for heating and cooling as transport and industry do. Some 75 percent of Germany’s buildings pre-date 1949 and use three to five times more energy than new-builds. Renovations to boost energy efficiency could therefore drastically reduce consumption.

Because renovating old buildings has such an important role to play in saving energy, many researchers are exploring the subject. They are seeking solutions to problems like how best to insulate a house, regulate moisture, and carry out renovations without wasting time or money.


Photo: Fraunhofer IBP

Researchers at the Fraunhofer Institute for Building Physics are using the Holzkirchen outdoor testing site (pictured) to investigate structures, building parts, building materials, and components for heating, ventilation and energy systems. They are working at full scale and under real climate and usage conditions.

Although there is little chance of pre-1949 buildings ever being efficient enough to produce their own energy, renovating them does offer enormous potential for reducing consumption.

SJanis Eitner, from the Fraunhofer Institute for Building Physics (IBP), answered this question.