 New Zealand has one of the highest asthma rates in the world, frequently linked to the quality of housing. A confirmed causal factor for asthma is the dust mite allergen, with environmental factors such as temperature and relative humidity (RH) linked to the proliferation of dust mites. Whilst significant research has been undertaken into the habitat and ecology of dust mites, little research has been conducted comparing different categories of housing quality in relation to dust mites.