Extension types
Types of house extension
Rear, side, wraparound, two-storey. They differ in what they cost, what the planning rules allow, and what they actually solve — which is the part most comparisons skip.
Two thirds of the people who ask us about extensions want a rear extension, and single storey outnumbers two-storey by about three to one (our quote tool, last 90 days). That does not make it the right answer for every house: if the problem is a shortage of bedrooms, ground-floor space will not fix it.
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Get free quotesWritten and checked by the HouseExtensionExpert editorial team · Last updated: 31 August 2026 · Planning and Building Regulations points are checked against current Planning Portal and GOV.UK guidance; cost ranges come from BestBuilders’ 2026 regional cost model (published national cost guides × a regional labour index, averaged across 519 UK towns). Ranges are indicative, not quotes.Next scheduled review: November 2026 · Spotted something out of date? Tell us.