Insights · Updated August 2026

Is a Home Extension Cheaper Than Moving House in 2026?

Moving to a larger home costs an upsizer roughly £28,000 in stamp duty, fees and removals — money that buys no extra space. A rear extension costs £45,000–£65,000 but becomes equity in your home. Here is the honest 2026 comparison, plus 3 free quotes.

Updated August 2026 Real 2026 cost data Vetted builders
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Extend or move — the 2026 verdict

If you like where you live, extending is usually the cheaper way to gain space.

  • Cost to move (typical upsizer): ~£28,000 in non-recoverable fees
  • Single-storey rear extension: £45,000 – £65,000
  • Value an extension typically adds: 10–15%
  • Moving wins when: you need a different location or plot

Moving costs vanish into stamp duty and fees; extension spend becomes equity. Net of the value added, an extension is often the lower true cost.

Moving vs extending: a 2026 cost comparison

Based on a typical upsizer selling a £400,000 home and buying a £550,000 one, versus adding a 25m² rear extension to the existing home. Beyond the raw numbers, the practical route matters. Many single-storey rear extensions fall under permitted development and avoid a full planning application, though larger builds, side returns and anything in a conservation area usually need consent, and every extension must still meet the Building Regulations for structure, insulation, drainage and fire safety. Where you share a boundary you will likely need a party wall agreement with neighbours before work starts, and a typical build runs to three or four months on site. For the detail, read our guide to planning a home extension step by step, check whether you need planning permission for a rear extension, and budget for the party wall surveyor cost.

Cost of Moving2026 Estimate
Stamp duty (on £550,000 purchase)£17,500
Estate agent fee (~1.2% + VAT on £400,000)£5,760
Conveyancing (buy + sell)£3,000
Removals£1,200
Mortgage & valuation fees£800
Total non-recoverable cost~£28,000

By contrast, a £45,000–£65,000 rear extension is largely recovered in added value. Stamp duty bands used: 0% to £125k, 2% to £250k, 5% to £925k (HMRC 2026). Your figures will vary by region and property value.

4 factors that decide extend vs move

Location

Do you love your area?

If schools, commute and neighbours already suit you, extending keeps all of that and avoids £28,000 of moving friction. If you need a different location, moving is the only real option.

Ceiling Price

Street value limit

If your home is near the top price for the street, an extension may not return its cost. Where there is headroom, the value uplift can offset most of the spend.

Space Needed

How much & what type

An extra reception room or bigger kitchen suits extending. A fundamentally larger house, more bedrooms and a bigger plot can be cheaper to buy than to build.

Disruption

Time & tolerance

An extension means 3–4 months of building work while you live in the house. Moving is faster to gain space but front-loads the cost in fees you never see again.

£28k
Typical cost to move (fees)
£45k+
Typical rear extension
15%
Value an extension can add
3
Free quotes to compare

Extend vs Move FAQs

It often is on a net basis. Moving costs roughly £25,000–£30,000 in stamp duty, agent fees, legal costs and removals — money that buys no extra space. A rear extension costs £45,000–£65,000 but becomes equity and typically adds 10–15% to your home's value. If you like your location, extending is usually the cheaper way to gain space.
For an upsizer buying at £550,000 and selling at £400,000, expect around £28,000: roughly £17,500 stamp duty, £5,000–£7,000 agent fees (about 1.2% + VAT), £2,500–£3,500 conveyancing, £1,000–£1,500 removals, and £500–£1,000 mortgage and valuation fees. None of it adds living space.
A single-storey rear extension costs £45,000–£90,000, or roughly £1,800–£2,500 per m². A typical 25m² kitchen-diner extension is £45,000–£65,000. Unlike moving fees, most of this is recovered in added value, so the true net cost of the space is far lower than the headline.
When you need a fundamentally different home or location — a better school catchment, shorter commute, or a bigger plot you cannot create by extending. It is also wiser when your home is near the ceiling price for the street, where an extension would not return its cost.
Usually, but not without limit. A well-designed extension typically adds 10–15% (more in London and the South East). The exception is the local ceiling price: spending heavily beyond what similar homes on your street sell for will not be fully recovered. Check comparable sales first.
Tell BestBuilders about your project and postcode and we will match you with up to 3 vetted local extension builders within 24 hours. Comparing three fixed-price quotes against the full cost of moving — including stamp duty and fees — is the only reliable way to know which is cheaper. Free with no obligation.

Compare Extending vs Moving — Get Real Quotes

Tell us about your project and we will match you with 3 vetted local builders. Free, no-obligation, no spam — just real prices to weigh against the cost of moving.

Reviewed by the BestBuilders editorial team · Last updated: 14 August 2026 · Next scheduled review: November 2026 · See our editorial standards.
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