Bronchiolitis is a common, often serious lung infection of children which can have serious short and long-term consequences. This project will explore risk factors in the home environment which potentially contribute to the striking and disproportionately high hospitalisation rate for bronchiolitis in Maori and Pacific children. We will investigate independent effects of poor quality housing, and indoor climate (temperature/humidity) on the development of childhood respiratory infections, and bronchiolitis severity. This Maori-led, community partnership project is a complementary and important addition to our existing case-control study. It utilises a kaupapa-Maori methodology to investigate disparities in bronchiolitis severity for both Maori tamariki and Pacific Island children. The research will: generate new knowledge of housing conditions for Maori and Pacific children; identify housing-related risk factors for avoidable hospitalisation; and inform policy to improve housing quality - to reduce the impact of respiratory disease for Maori and Pacific children.