Retrofit Designer cost (UK 2026)

A Retrofit Designer engaged on a Path B or C project charges £800to£3,000 on a typical single-property job. Bespoke detailing on a listed building or system-built property reaches £5,000 plus.

Mandatory on Path B and Path C. Optional on Path A. The Designer's hygrothermal modelling is often the single most valuable PAS 2035 deliverable on a solid-wall IWI project.