Case studies of cavity and external wall insulation retrofitted under the Irish Home Energy Saving Scheme: Technical analysis and occupant perspectives

The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government's national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all cases. Regardless, the occupant played a considerable role in the change in energy use in the buildings, and the main motivation for retrofit was found to be comfort and not energy savings or environmental concerns. As a result, the actual energy savings are notably less than the potential savings had the pre and post comfort levels remained the same.