Passive houses in Saxony, Germany

Saxony has identified a large CO2 reduction potential in the heat supply of buildings. The so-called passive houses consume around 15kWh/m²/year which is at least 3-5 times less than low energy houses and 7-20 times less than existing buildings. Saxony started its first pilot project "Innovation and Practice Network Passive Houses" as early as 2002. Since then the number of passive houses has increased significantly. Saxony financially supports builders and provides a lot of information including on-site visits.

This was the motivation for the study visit following the EnercitEE kick-off meeting when Working Group and Steering Group members could see and understand the quality requirements of building materials and quality checks being performed.

The passive house expert from the Saxon State Ministry for Economic Affairs, Labour and Transport, Dr. Bernd Wolters organised a tour starting from the Ministry passing several passive houses such as the main state archive of Saxony and ending at a kindergarten which was still under construction. The technical issues of the passive house building approach can be understood much easier when seeing the process itself and the material used.

The tour through the construction site was guided by the architect, Guenther Rentzsch who explained the technical details and showed how waste heat from the discharged air will be used again in the passive house. He also pointed out the difficulties in testing if a building really meets the required standards. Mr. Rentzsch introduced the participants to a special pressure test for passive houses that is called the ‘blower-door’. This test makes any air leakages immediately visible.

It is carried out when interior fittings are complete (windows, facades, etc.). The craftsmen who should be involved in the building process have to be present during this test. This visual proof is accepted by all affected companies which will readjust certain details after this test.

Corresponding documents for download (PDF-files)