The idea of a passive house comes from a Swedish architect Bo Adamson and a German civil engineer Wolfgang Feist. In 1988 they created the concept of a Passive House, which constituted the basis for the first passive house built in Darmstadt, Germany in 1991. It was a semidetached house with four apartments, each having a total living area of 156 m2. Since then passive houses have gained popularity around the world, especially in Central Europe and Scandinavia.
What is the difference between passive houses and traditionally built houses? The difference of a passive house is in its high thermal insulation and airtightness, which significantly reduces heat losses. At the same time these buildings are designed in a way to prevent them from overheating and ensure comfortable indoor climate both in winter and summer.
In order for a house to be considered passive, it must meet the following requirements:
- the annual specific heat consumption for space heating is less than 15 kWh/m² OR the maximum heating load per square meter of living space does not exceed 10 W/m²
- the annual specific space cooling energy consumption does not exceed 15 kWh/m²
- the overheating frequency (indoor temperature more than 25°C) is less than 10%
- airtightness test n50 ≤ 0.6 air change/h
- the total annual primary energy consumption is less than 120 kWh/m²
New technologies are being developed, more precise measurements enable improvements in construction process, however, the basic principles of passive houses laid down thirty years ago have remained the same.