In developed countries we spend most of our time indoors and most of that time is spent inside our homes (Baker, Keall, Lyn Au, & Howden-Chapman, 2007), so the quality of the indoor environment is crucial to occupants' health and wellbeing (World Health Organization Regional Office for Europe, 2009). Moreover, indoor air is only a chimney, an open window, or a door away from being outdoor air, so the quality of indoor air matters, both for outdoor air and the climate in general.
The design and maintenance of homes is a key factor in determining the wellbeing of the occupants, both inside and outside their homes. Most existing housing has not been built under modern building code standards, which, in any case, vary considerably across the developed world, so retrofitting insulation in existing housing is an important policy to improve health and wellbeing.
In this chapter we look at the growing international evidence that insulating houses improves health and wellbeing, as well as having many cobenefits, including reducing fuel poverty, increasing energy efficiency, mitigating climate change, and providing employment. We also analyze the different frameworks that have been used to justify insulation policies and summarize the outcomes of several large-scale programs.