Key Facts: Conservation Area Extensions in London (2026) Extending a property in a London conservation area costs 15 to 30% more than an equivalent extension on an unrestricted site, due to material requirements, additional planning work, and longer determination timescales. Most single-storey rear extensions in conservation areas require a full planning application rather than permitted…
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House Extension Costs in London: The Complete 2026 Guide
Key Facts: House Extension Costs in London (2026) An architect-designed house extension in London costs between £3,000 and £5,000+ per square metre in 2026, depending on specification and borough. For a typical single-storey rear extension of 20 to 30 m², expect a total project cost of £80,000 to £150,000 including construction, fit-out, professional fees, and…