CEPHEUS – measurement results from more than 100 dwelling units in passive houses

Panel: Panel 2. Comfort and energy use in buildings

Author:
Jürgen Schnieders, Passive House Institute

Abstract

Passive houses offer extended living comfort with only 15 to 20 % of the space heating demand of conventional new buildings. This is achieved by improving the efficiency of building components, such as walls, windows or ventilation system, which are necessary in every building anyway. Thus, the extra costs of this standard are only about 10 % of the total building costs. Within the EU-funded demonstration project CEPHEUS (Cost Efficient Passive Houses as EUropean Standards), 14 passive houses with 221 dwelling units have been built at different building sites, with different planners and users and of different construction types. In this paper, detailed measurements for 11 passive house projects are presented.

All projects show extraordinarily low space heat consumption with an average during the first heating season of 20 kWh per square metre living area. Compared with newly erected buildings that obey local legal standards, 80 % of the space heat consumption could be saved. In addition, the total primary energy consumption (including household electricity) was less than 50 % of that of conventional new buildings.

The mean room temperature in the heating period was 21.4 °C. Even at very low outdoor temperatures the room temperatures did not go down significantly. The measurements show that the buildings also offer comfortable summer conditions. Indoor temperatures rarely rose above 25 °C.

Users were well pleased with the simple techniques used. Even with tenants in low-income housing the projected energy savings could be reached. A social research project showed a high degree of user satisfaction.