Passivhaus is the most widely recognised international standard for energy efficient buildings. It covers new-build houses but also schools, offices, and public buildings, along with a similar standard for refurbished buildings (EnerPHit). It all started with an academic research project in the 1980’s, the compelling logic of which prompted four families to combine resources and build the original passive house for themselves – a group of four terrace houses in Darmstadt-Kranichstein, Germany, completed in 1991.

The building is best described by the following quotes from the Passivhaus Institute website. The originators of the concept were Wolfgang Feist, Bo Adamson, Gerd Hauser and Robert Hastings.

In the mid-1980s the low-energy building was already a legally required energy standard for new buildings in Sweden and Denmark. Even at that time, the further development of the principles of low-energy housing was being considered, i.e. excellent insulation, prevention of thermal bridges, airtightness, insulated glazing and controlled ventilation. Based on these considerations, the “Passive House” was launched in May 1988.

“Passive Houses” were defined as buildings which have an extremely small heating energy demand even in the Central European climate and therefore need no active heating. Such houses can be kept warm “passively”, solely by using the existing internal heat sources and the solar energy entering through the windows as well as by the minimal heating of incoming fresh air.

In 1990/91, based on plans by Prof. Bott/Ridder/Westermeyer, four terraced house residential units were built by for families in a joint venture. The houses have been occupied since 1991. An accompanying monitoring programme provided information about super-insulated building components, windows, ventilation heat recovery, user behaviour, indoor air quality, amount of internal heat sources and much else.

As of 2010, the same four families are still living in the first Passive House in Darmstadt Kranichstein and the measured space heating demand remains 10 kWh/(m²a). No large maintenance measures have yet been undertaken and all building services remain unchanged from their original configuration. The facade, roof and windows remain unchanged.

What is important is that the occupants of the Passive Houses feel happy in their homes. Theory and practice are in agreement here; due to very good thermal insulation the interior surface temperatures are high everywhere, even at freezing outdoor temperatures. Draughts and differing radiant temperatures are thus prevented. This has been confirmed by measurements in built houses.

Passivhaus is one of several certification schemes operating for ecohouses.