A Swedish - German energy efficient apartment building with attached sunspace.

Two identical apartment buildings were built, one in Germany, and one in Sweden, in 1986. The idea was to create energy efficient housing at a low cost, using Swedish building technology and German heating and ventilation technology. The Swedish building code, which is more stringent in terms of energy conservation than the German one, was applied in both countries. The paper examines the performance of the buildings. The energy consumption (1987-89) for space heating was 45 % less than for a building built according to the Swedish building code and 60 % less than a building built according to the German building code. These energy savings were achieved by insulating the buildings very well and by installing an exhaust air heat pump. Less than 5 % of the total energy savings were due to the sunspace and the thermal mass. The energy efficiency can be further improved.