Evidence base for a housing warrant of fitness.

Substandard housing is a major public health issue in New Zealand. Approximately, two-thirds of the housing stock is uninsulated and many homes are inadequately heated, with an average indoor temperature of 14.5°C. Cold, damp, and mouldy housing results in poor health; each year, respiratory hospital admissions are 74% higher during winter, and excess winter mortality is 20% higher than other seasons. The relationship between injury and housing conditions is also well established. Each year, 500,000 New Zealanders suffer falls requiring medical treatment in their homes. As a step towards improving the quality of existing housing, an evidence-based warrant of fitness has been developed. This article outlines the evidence base to each criterion in the warrant of fitness. We conclude that introducing and properly enforcing a housing warrant of fitness will ensure that basic minimum standards are met, which could mitigate the disease burdens and injuries associated with, or caused, by poorer quality housing. In addition, there are potential fiscal and economic advantages of the scheme, including reduced hospitalisations and increased productivity.