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The most important principle of a Passive House: insulation (yellow), applied continuously around the building envelope without thermal bridging - this reduces the heat losses like a warm coat. Most insulation materials are not airtight, however. Therefore the envelope has to be airtight, too. The airtight envelope can be seen in the section, too - it is given by the red line. The reduction of thermal bridges is very important; A special design method, the "Construction Avoiding Thermal Bridging" has been developed to simplify this design detail.

In a Passive Home the whole building envelope has an excellent thermal insulation. The envelope consists of all parts of the construction, which separate the indoor climate from the outdoor climate. All construction methods can be used for Passive Houses and have been tested successfully: masonry construction, lightweight construction, prefabricated elements, insulating concrete formwork construction, steel construction, and all combinations of the methods above.

The thermal heat loss coefficients (U-Values) of external walls, slabs to the ground, and roofs are within 0.1 to 0.15 W/(m²K) (for Central European climate; other climates will be discussed at the conference). These are upper level values for all contemporary constructions. As a consequence the transmission heat losses during the cold season are negligible. Another consequence is that the temperatures of the internal surfaces are almost the same as the indoor air temperature. This leads to a very comfortable indoor climate and avoids damages caused by the humidity of indoor air.

During hot periods in summer, a high thermal insulation is a protection against heat, too. To ensure high thermal comfort during summer, well designed shading and sufficient ventilation are important, too.

Good thermal insulation and an airtight construction are well proved in Passive Houses. Another basic principle used is "Construction Avoiding Thermal Bridging": The insulation is applied continuously around the envelope of the building without serious thermal bridging. By this method there will be no cold spots and no increased heat losses. This is a contribution to high quality, comfortable, and long lasting construction, too.

11th International Conference on Passive Houses:

Experience with insulation, air tightness, and innovative methods for the building envelope will be discussed in the Workshop "Reserach and Development". Insulation is efficient for energy conservation, increasing thermal comfort in existing buildings, too. This will be shown by retrofit examples in Workshops on using Passive House components for refurbishment.

Top products of insulating components will be presented in the exhibition - some with models of original size.

Additional information on insulation suitable for Passive Houses

(updated: 2006-09-23 thanks to Dylan Lamar for proof reading
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