PAS 2035 for homeowners: why it matters which standard your installer works to

PAS 2035 is the whole-house retrofit standard that came into force in 2019 and has been required for most government-funded retrofit work since 2021. It changed the industry by requiring that retrofit be approached systematically — not as a series of individual product installations.

Under PAS 2035, every significant retrofit project must be led by a qualified Retrofit Coordinator, informed by a Retrofit Assessment, and delivered in a sequence that considers how measures interact. The standard exists because poorly planned retrofit can cause real problems — damp, condensation, structural issues — when measures are installed without understanding the building as a whole.

For homeowners commissioning any significant energy upgrade, the question to ask is simple: does your installer work to PAS 2035? If the answer is no, or if they're not sure what it is, that's useful information.