Poor housing is associated with poor health. This suggests that improving housing conditions might lead to improved health for residents. This review searched widely for studies from anywhere in the world which had investigated whether or not investment to improve housing conditions is linked with improvement in health. A huge amount of research on housing and health has been published but very few studies have investigated if improved housing conditions impact on residents' health. Neighbourhood renewal programmes often include housing improvements but a key aim of these programmes is to improve the area by attracting new residents, often those who are better off. In these programmes, improvements in health statistics may simply reflect a change in the population living in an area and the original population may not have benefited from the improved living conditions. This review only looked at studies where changes in health for the original population were being investigated rather than changes for the area.
We identified 39 studies which assessed changes in health following housing improvement. The studies covered a wide range of housing improvements. The housing improvements in high income countries, and conducted in the past 30 years, included refurbishment, rehousing, relocation, installation of central heating and insulation. Studies from the developing world included provision of latrines. Older studies (pre-1965) examined changes in health following rehousing from slums. Overall, it would appear that improvements to housing conditions can lead to improvements in health. Improved health is most likely when the housing improvements are targeted at those with poor health and inadequate housing conditions, in particular inadequate warmth. Area based housing improvement programmes, for example programmes of housing-led neighbourhood renewal, which improve housing regardless of individual need may not lead to clear improvements in housing conditions for all the houses in a neighbourhood. This may explain why health improvements following these programmes are not always obvious.
Improvements in warmth and affordable warmth may be an important reason for improved health. Improved health may also lead to reduced absences from school or work. Improvements in energy efficiency and provision of affordable warmth may allow householders to heat more rooms in the house and increase the amount of usable space in the home. Greater usable living space may lead to more use of the home, allow increased levels of privacy, and help with relationships within the home. An overview of the best available research evidence suggests that housing which promotes good health needs to be an appropriate size to meet household needs, and be affordable to maintain a comfortable indoor temperature.