Airtightness of apartments - Build 180(2020)
- Airtightness of apartments
- Valid from
- Information provider
- BRANZ Limited
- Information type
- BUILD article
- Website, PDF
Recent BRANZ research into the airtightness of apartment buildings has prompted a shift in thinking around airtightness and ventilation. BRANZ now recommends that residential buildings are mechanically ventilated and are built to an airtightness target.
The airtightness of a building is a measure of how much air flows between indoors and outdoors through the structure itself – in other words, how big the holes are in the structure.
Airtightness is a key aspect of a building’s performance, affecting the energy efficiency, thermal comfort and indoor air quality. However, airtightness is only mentioned indirectly in the New Zealand Building Code, and there is no requirement to meet a particular target level of airtightness.
This article includes:
- BRANZ tested a range of apartments
- Airtightness similar to new standalone houses
- Airtightness ranged from 1.9–12.6 ach
- Many homes underventilated
- Aim for 3 ach @ 50 Pa
- Move to mechanical ventilation
- Only small improvement needed
- Resources to help achieve airtightness
- Dealing with air leakage
- A different approach