Energy
Designing homes to conserve energy and use it efficiently, from sources that cause least environmental harm.
Active ventilation
Ventilation is required to remove moisture and airborne pollutants from a home to protect the health and comfort of people living there. Ventilation can also be important for temperature control, particularly in summer.
In most New Zealand homes, passive ventilation will be sufficient for most of the year and only localised air extraction systems are needed: range hoods in the kitchen and extractor fans in bathrooms.
However, in some situations, an air supply ventilation system or heat recovery ventilation (HRV) system may be necessary where passive ventilation is not sufficient to meet New Zealand Building Code requirements.
A true HRV system supplies fresh air from outdoors that is warmed by the heat extracted from the air being removed from indoors; it does not simply recycle roof space air.