ER90 Natural ventilation in damp homes – a qualitative exploration of behaviours and interventions for change (2024)

Home-occupant behaviour in respect to ventilation in Aotearoa New Zealand is under-researched, despite the benefits that a well-ventilated building may have on respiratory health. Most Kiwi homes rely on natural ventilation by opening windows, which is occupant controlled. As the climate changes, natural ventilation will be increasingly important not just for reducing moisture but for reducing exposure to high indoor temperatures without increasing energy costs and carbon emissions. This research aimed to understand how and to what extent people ventilate their homes, and ways in which ventilation might be improved.

The project examined previously collected data to identify patterns of ventilation that are most closely associated with reduced indoor humidity and low indoor mould levels. The researchers interviewed housing assessors and whānau living in homes with known dampness issues.

Using this knowledge, the researchers piloted a low-cost intervention aimed at improving ventilation behaviours. The effectiveness was monitored using a sensor system that will alert occupants to poor ventilation in their living areas. Researchers assessed the levels of indoor mould before and after the intervention, followed by interviews with participants about their experiences.

The analysis of the data seeks to establish a baseline of standard ventilation practice in Aotearoa New Zealand. It identified whether a low-cost intervention could change people’s ventilation behaviours to reduce indoor relative humidity and visible mould in Kiwi homes.