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Move or extend in Tower Hamlets? 2026 cost comparison

For homeowners in Tower Hamlets (London Borough of Tower Hamlets). Updated 2026-06-11.

Inner east London. Georgian terraces in Spitalfields and Wapping; early-Victorian terraces in Tredegar Square and Bow; substantial postwar council estates and recent high-density development in Canary Wharf (E14). Period stock tightly conservation-area controlled; side returns rare on the older listed/conservation streets.

The borough covers the E1, E1W, E2, E3, E14 postcode districts. Terraced homes here trade around £875,000 against the borough-wide £555,000 average.

In short

In Tower Hamlets, the average home is valued at £555,000. Moving up by 60% to a £890,000 property triggers approximately £34,500 in Stamp Duty Land Tax (SDLT). By contrast, a 12 m² high-spec side return extension here costs around £82,524 all-in. Tower Hamlets has 58 conservation areas — among the most of any London borough.

Your numbers

Adjust the inputs to see your scenario. The page updates instantly as you adjust the inputs.

Property values

Our tool assumes your new property costs more than your current one.

Recommended types reflect Tower Hamlets's typical housing stock.

Spec tier
12 m²
Advanced: buyer profile

Your result

Moving is £20,349 cheaper than extending

Move

Total: £62,175

SDLT (HMRC)
£34,500
Estate-agent fee
£8,325
Survey
£1,500
Legal (sale + purchase)
£2,500
Removals
£2,000
Chain contingency (1.5%)
£13,350

Extend

Side return extension — high spec

Total: £82,524

Build cost (12 m² × £4,600/m²)
£55,200
Professional fees (15%)
£8,280
Subtotal
£63,480
VAT (20%)
£12,696
Contingency (10%)
£6,348

An extension of this type and size could add roughly £72,150 (≈13%) to your home's value — Nationwide Building Society, October 2025.

Your tipping line

Where moving starts costing more than the extension you selected. The chart follows your inputs above.

£150k£300k£450k£550k£2.3m£4mTarget property valueMovingExtendingYour target£1.1m — tipping line

Up to about £1,085,000 of target price, moving is the cheaper route in Tower Hamlets; beyond that line, extending wins.

Extending in Tower Hamlets: what's different here

Local planning picture

Conservation areas
58
Householder decisions within 8 weeks
61%
Build-cost tier
inner London
Typical housing stock
Victorian and Edwardian terraces

Decision speed: MHCLG householder statistics, year ending September 2025, excluding agreed extensions of time.

Worth knowing in Tower Hamlets

  • Tower Hamlets has 58 conservation areas — among the most of any London borough.
  • The average home here is around £555,000 (ONS, 2026).
  • Extension types suited to Victorian and Edwardian terraces: Side return extension, Rear extension (single storey), Wrap-around extension, Kitchen extension, Loft conversion (dormer), Loft conversion (mansard).

How the £34,500 stamp duty stacks up

HMRC bands applied to a £890,000 purchase — the default Tower Hamlets trade-up.

Price band Rate SDLT due
£0 – £125,000 0% £0
£125,000 – £250,000 2% £2,500
£250,000 – £925,000 5% £32,000

What each suitable type costs vs the £62,175 move

High specification at typical size, inner London rates, all-in.

Extension type All-in cost vs moving
Side return extension (12 m²) £82,524 £20,349 more than moving
Rear extension (single storey) (22 m²) £124,982 £62,807 more than moving
Wrap-around extension (25 m²) £108,388 £46,213 more than moving
Kitchen extension (22 m²) £124,982 £62,807 more than moving
Loft conversion (dormer) (18 m²) £47,093 saves £15,082 vs moving
Loft conversion (mansard) (30 m²) £103,155 £40,980 more than moving

Why this comparison matters

"An architect-designed house extension in London may cost between £3,000 and £5,000 per square metre. Elsewhere in the UK, you can expect to pay between £2,000 and £3,500 per square metre."
— Architecture for London

Frequently asked questions

Is it cheaper to extend or move in Tower Hamlets?
At Tower Hamlets's average £555,000 home moving up to £890,000, the move costs about £62,175 — including £34,500 of HMRC Stamp Duty. A 12 m² high-spec side return extension runs roughly £82,524 at inner London rates. Moving is cheaper here by about £20,349. Your real figure depends on extension size, specification and planning constraints.
How long does a side return extension take in Tower Hamlets?
Allow around 16 weeks on site for a typical side return extension in Tower Hamlets, after design, party wall agreements with neighbours and the council's determination period. A rear extension (single storey) runs nearer 16 weeks. End to end, plan 4–8 months from first call to completion — longer in conservation areas or where structural surveys are needed.
Will an extension add value to my Tower Hamlets home?
Nationwide Building Society (October 2025) found that adding a double bedroom can lift a home's value by about 13%, and a full loft conversion plus extension by up to 24%. On a Tower Hamlets average of £555,000, that's roughly £72,200 to £133,200 of capital uplift. Final return depends on the local market, the type of buyer in Tower Hamlets, and your extension's specification.
Can I live in my home during the extension build?
Most Tower Hamlets families stay in their home during a single-storey rear or side return extension — the build is contained to the back, and your kitchen is typically rebuilt in 2–3 weeks of disruption. Loft conversions and full wraparounds are harder: expect 4–6 weeks where one floor is unusable. Plan for temporary kitchen arrangements and dust everywhere.
At what price does moving stop making sense in Tower Hamlets?
Starting from Tower Hamlets's average £555,000 home with a 12 m² high-spec side return extension (£82,524 all-in), the tipping line sits at roughly £1,085,000: buying above that price costs more in SDLT and moving fees than the extension itself. Below it, moving stays the cheaper route. The live chart on this page recalculates the line for your own inputs.
How much stamp duty would I pay moving up in Tower Hamlets?
On a typical Tower Hamlets trade-up from £555,000 to £890,000 (a 60% step up), Stamp Duty Land Tax (SDLT) is £34,500 — an effective rate of 3.88%. First-time buyers and additional-property buyers pay different rates. Use HMRC's official calculator at tax.service.gov.uk for your exact figure. HMRC Stamp Duty calculator
What does a typical extension cost in Tower Hamlets in 2026?
A 12 m² side return extension in Tower Hamlets runs about £83,000 all-in at high specification, on inner London build rates of around £4,600/m². A 22 m² rear extension (single storey) comes to roughly £125,000. All-in figures include 15% professional fees, 20% VAT and a 10% contingency — final cost depends on access, specification and ground conditions.
How long does planning permission take in Tower Hamlets?
The statutory determination period for a householder application is 8 weeks. London Borough of Tower Hamlets decided 61% of householder applications within 8 weeks in the year to September 2025 (MHCLG figures, excluding agreed extensions of time). Across London, authorities grant roughly low-to-mid 80s per cent of applications. A householder application costs £548 from April 2026, and a Larger Home Extension prior approval £240.
Do I need planning permission for an extension in Tower Hamlets?
Many single-storey rear extensions fall under Permitted Development — no planning permission needed. Tower Hamlets operates Article 4 directions covering its many conservation areas (notably Spitalfields, Tredegar Square, Wapping, Limehouse) plus a borough-wide HMO Article 4. The Spitalfields and Tredegar Square directions remove most external alteration PD rights — the borough's Georgian and early-Victorian terrace stock is tightly controlled. Tower Hamlets has 58 conservation areas, including Spitalfields, Tredegar Square, Wapping, where PD rights are curtailed. Side extensions, large rear extensions and most wraparounds need full planning regardless. Check the London Borough of Tower Hamlets planning portal first. Open the London Borough of Tower Hamlets planning portal

Compare nearby London boroughs

Nearby by average property value — useful if you're weighing a move to an adjacent price tier. A comparable trade-up in Merton would carry about £35,250 of stamp duty — £750 more than in Tower Hamlets.

See all 33 London boroughs

Methodology and sources

Stamp Duty Land Tax is calculated from the HMRC bands in force for the 2025–26 tax year. Verify any figure against HMRC's official calculator before committing. Extension costs use inner London £/m² rates by extension type — industry-estimate midpoints, presented as approximations.

  • London 2026 £/m² grid by extension type and tier — Build Team benchmark compiled from BCIS/RICS, FMB and published architect guides (refreshed quarterly).
  • Conservation-area counts and Article 4 status — individual London borough councils, verified 2026.
  • HMRC SDLT calculator — tax.service.gov.uk/calculate-stamp-duty-land-tax
  • GOV.UK Stamp Duty Land Tax guidance — gov.uk/stamp-duty-land-tax
  • Nationwide House Price Index (October 2025 release) — value-add commentary attributed to Andrew Harvey, Senior Economist.
  • HM Land Registry / ONS UK House Price Index — borough average property values (March 2026 release).
  • MHCLG planning statistics (PS2 dashboard) — householder decision speed, year ending September 2025.