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.

The untapped / hidden benefits of environmental policies are huge, this piece of research showcases and places a monetary value on the added benefits to our health, society and the economy that environmental investments and policy linked to energy efficiency can bring. Findings show that green policies can improve both our health and the economy and can go hand-in-hand. This study provides guidance to policy and decision-makers in developing a methodology for the inclusion of multiple benefits in a cost/benefit assessment of energy efficiency policy.