New Zealand homes and apartments have become more and more airtight and have reached a level of airtightness that requires dedicated ventilation. Despite the fact that there is no airtightness requirement in the New Zealand Building Code, new homes regularly reach an airtightness level of 2-3.5 ACH50. This can be a welcome trend as it allows controlled ventilation and therefore control of the energy demand of the building. Many newly built homes, however, experience excess moisture and mould problems in living areas and/or roof cavities, due to a combination of occupant behaviour and a lack of ventilation.
The goals of a healthy home environment and energy efficiency can sometimes pull in opposite directions, requiring us to find a trade-off between health and energy saving.
Do we need dedicated airtightness and ventilation targets in the Building Code to reach an optimal set point for ventilation related energy use and health outcomes? How can this be achieved?
The objective of this AIVC workshop was to discuss and identify ways to improve the quality of our homes with respect to airtightness and ventilation, as well as discussing the impact suboptimal performance has on energy consumption and health of the occupants. Also of interest are the impacts of mandatory airtightness targets and how best to implement these, if at all.