Building terms, in plain English
Key Passive House and high-performance building terms used across the Knowledge Centre.
- Passive House
- An international building standard for very low energy homes that stay warm, dry and healthy, achieved through high insulation, airtight construction, high-performance glazing, thermal-bridge-free detailing and mechanical ventilation with heat recovery. In New Zealand it is administered by PHINZ.
- MVHR (Mechanical Ventilation with Heat Recovery)
- A whole-home system that continuously supplies filtered fresh air and extracts stale air, recovering most of the heat from the outgoing air to pre-warm the incoming air.
- Thermal bridge
- A localised path in the building envelope where heat escapes more easily, for example a structural element bridging the insulation, causing heat loss and possible condensation. Passive House design aims to be thermal-bridge-free.
- Airtightness
- How well the building envelope resists uncontrolled air leakage, measured by a blower-door test as air changes per hour at 50 pascals (ACH50). The Passive House standard requires 0.6 ACH50 or lower.
- Homestar
- A New Zealand residential rating tool administered by the New Zealand Green Building Council that rates a home for health, comfort and efficiency from 6 to 10 stars.
- R-value
- A measure of thermal resistance. Higher R-values mean better insulation performance and less heat loss.