The existing residential building stock accounts for a substantial portion of worldwide energy consumption and greenhouse emissions. Improvements to the thermal performance of existing buildings is a vital activity to mitigate climate change, and often has additional benefits in the form of improved comfort, health and well-being for occupants. Despite the extensive body of literature in this area, it remains a difficult task to assess the performance of retrofit packages in occupied residential buildings.

To date, greenhouse gas (GHG) emissions, mitigation strategies and the accompanying health co-benefits in different economic sectors have not been fully investigated. The purpose of this paper is to review comprehensively the evidence on GHG mitigation measures and the related health co-benefits, identify knowledge gaps, and provide recommendations to promote further development and implementation of climate change response policies.

The building sector is not on track to lower total greenhouse gas emissions. Given that emissions from the sector represent nearly 40% of global energy-and process-related emissions, this represents a serious challenge to keeping global warming to 1.5oC. The Buildings sector must therefore decarbonize.To support this goal, this report focuses on policy drivers for decarbonisation, and the costs and benefits associated with their implementation.