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Advice for building in Kent

Plain answers for anyone planning building work: what extensions and roofs really cost, when you need planning permission, and how to look after a period or listed property. Every figure is sourced, and every guide is written with the Risdon team.

15 October 2026 · 13 minute read

How much does an extension cost?

What an extension really costs in 2026: price per m², totals by size, VAT, fees and timelines, with a 20m² Kent budget added up line by line.

Inside this guide

Cost per m², by finish
A 20m² extension, added up
VAT and the fees on top
How long it takes

William GuthrieHead of Marketing, Risdon Renovations

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What we build

Planning something specific? Each topic below goes to the work itself, with photos of finished jobs.

Extensions
Roofing
Garden rooms
Period and listed homes
Planning and design

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Advice for building in Kent

How much does an extension cost?

What we build

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