Insulation before heat pump: why the sequence matters more than the brand

The sequencing of retrofit measures matters enormously — and getting it wrong can undermine the performance of an otherwise excellent installation.

A heat pump in a poorly insulated home is working against itself. It's designed to deliver low-temperature heat efficiently, but a leaky building envelope means that heat escapes faster than the system can maintain comfort. The result is higher running costs, reduced efficiency, and a customer who concludes that heat pumps 'don't work'.

Our standard approach is to assess the fabric first, prioritise insulation measures that will have the biggest impact on heat loss, and only then design the heating system. This is also the approach mandated by PAS 2035 — the whole-house retrofit standard.