Evidence from low-energy houses, such as passive houses, shows that they are comfortable, with good air quality and with no draughts or down draughts. A passive house requires minimal additional heating, while maintaining a comfortable indoor climate all year round.

Low-energy buildings typically use heat recovery ventilation, which help to ensure optimal air quality. With good filtration systems, pollen and dust can be effectively removed from incoming, outside air and the "bad" air from inside can be filtered out.

The sound level in a passive house is very low thanks to the thickness of the walls and the extra insulation in the windows. Noise levels from the ventilation system are also very low.

Energy efficient buildings can be designed any way you want. There are, however, some things to take into consideration, such as building orientation and window type and placement. But with good planning there are no real restrictions.

Energy efficient buildings are not bound to a specific type of construction and examples of passive houses have been designed based on different types of buildings, such as concrete, brick and wooden-frame houses. The passive house concept is also adaptable for both refurbishment and construction of large residential, commercial and public buildings such as schools, shops or office buildings.

An important factor of the passive house concept is quality assurance. Moisture resistibility of the building materials are carefully inspected, which reduce the risk for mould, and the sealing technique ensures that damp interior air is never forced into the building structure or that emissions from the building materials are forced into the house.

Source:
International Energy Agency
Passivhuscentrum (Passive House Centre), Sweden