A Passivhaus building is a low-energy structure that allows for space heating and cooling-related energy savings of up to 90% compared with typical building stock and over 75% compared to average new builds.
Passivhaus make efficient use of the sun, internal heat sources and heat recovery, rendering conventional heating systems unnecessary throughout even the coldest of winters. During warmer months, Passivhaus properties make use of passive cooling techniques such as strategic shading to keep comfortably cool.
Passivhaus buildings are praised for the high level of comfort they offer. Internal surface temperatures vary little from indoor air temperatures, even in the face of extreme outdoor temperatures.
Special windows and a building envelope consisting of a highly insulated roof and floor slab, as well as highly insulated exterior walls, keep the desired warmth in the house – and undesirable heat out.
In addition, a ventilation system imperceptibly supplies constant fresh air, making for superior air quality without unpleasant draughts. A highly efficient heat recovery unit allows for the heat contained in the exhaust air to be re-used.
Passivhaus properties use less than 1.5 l of oil or 1.5 m3 of gas to heat one square metre of living space for a year – substantially less than common “low-energy” buildings. Vast energy savings have been demonstrated in warm climates, where typical buildings also require active cooling.