The Extension Works
UK only: we design and build extensions in London & the South East of England (Surrey, Hampshire & Berkshire) — we can’t quote for projects outside the UK.
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sustainable home extensions

10–15 Year Payback: Fabric First Extension Design in England

England homeowners: a fabric first guide to meet Part L and Part O, hit U values and airtightness targets, and secure a performance aware quote.

The Extension Works 4 September 2026
10–15 Year Payback: Fabric First Extension Design in England