ON SITE

Insulation and airtightness: Watchpoints

Your insulation and airtightness strategy will have been worked out at this stage with your energy assessor. For both insulation and airtightness the trickiest bits of the installation tend to be at the junctions, between wall and roof, windows and cavity wall, etc., to avoid thermal bridging. Existing homes present the challenge of working with some unknowns, and you may need to revise the insulation and airtightness strategy once elements have been stripped back.