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Move or extend in Newham? 2026 cost comparison

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

Inner east London. Predominantly Victorian and Edwardian terrace stock across the older wards (Forest Gate, Plashet, East Ham, Manor Park, West Ham). Substantial recent regeneration in Stratford (E20), Canning Town and Custom House. Side returns common in the older wards.

The borough covers the E6, E7, E12, E13, E15, E16, E20 postcode districts. Terraced homes here trade around £470,000 against the borough-wide £402,000 average.

In short

In Newham, the average home is valued at £402,000. Moving up by 60% to a £645,000 property triggers approximately £22,250 in Stamp Duty Land Tax (SDLT). By contrast, a 22 m² high-spec rear extension (single storey) here costs around £108,537 all-in. Newham has just 9 conservation areas — among the fewest in London.

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 Newham's typical housing stock.

Spec tier
22 m²
Advanced: buyer profile

Your result

Moving is £64,582 cheaper than extending

Move

Total: £43,955

SDLT (HMRC)
£22,250
Estate-agent fee
£6,030
Survey
£1,500
Legal (sale + purchase)
£2,500
Removals
£2,000
Chain contingency (1.5%)
£9,675

Extend

Rear extension (single storey) — high spec

Total: £108,537

Build cost (22 m² × £3,300/m²)
£72,600
Professional fees (15%)
£10,890
Subtotal
£83,490
VAT (20%)
£16,698
Contingency (10%)
£8,349

An extension of this type and size could add roughly £52,260 (≈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£400k£2.2m£4mTarget property valueMovingExtendingYour target£1.3m — tipping line

Up to about £1,332,000 of target price, moving is the cheaper route in Newham; beyond that line, extending wins.

Extending in Newham: what's different here

Local planning picture

Conservation areas
9
Householder decisions within 8 weeks
63%
Build-cost tier
outer London
Typical housing stock
1930s semi-detached homes

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

Worth knowing in Newham

  • Newham has just 9 conservation areas — among the fewest in London.
  • The average home here is around £402,000 (ONS, 2026).
  • Extension types suited to 1930s semi-detached homes: Rear extension (single storey), Rear extension (double storey), Two-storey side extension, Garage conversion, Loft conversion (hip-to-gable), Over-garage extension.

How the £22,250 stamp duty stacks up

HMRC bands applied to a £645,000 purchase — the default Newham trade-up.

Price band Rate SDLT due
£0 – £125,000 0% £0
£125,000 – £250,000 2% £2,500
£250,000 – £925,000 5% £19,750

What each suitable type costs vs the £43,955 move

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

Extension type All-in cost vs moving
Rear extension (single storey) (22 m²) £108,537 £64,582 more than moving
Rear extension (double storey) (45 m²) £208,553 £164,598 more than moving
Two-storey side extension (35 m²) £167,440 £123,485 more than moving
Garage conversion (18 m²) £43,056 saves £899 vs moving
Loft conversion (hip-to-gable) (25 m²) £67,275 £23,320 more than moving
Over-garage extension (18 m²) £34,983 saves £8,972 vs 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 Newham?
At Newham's average £402,000 home moving up to £645,000, the move costs about £43,955 — including £22,250 of HMRC Stamp Duty. A 22 m² high-spec rear extension (single storey) runs roughly £108,537 at outer London rates. Moving is cheaper here by about £64,582. Your real figure depends on extension size, specification and planning constraints.
How long does a rear extension (single storey) take in Newham?
Allow around 16 weeks on site for a typical rear extension (single storey) in Newham, after design, party wall agreements with neighbours and the council's determination period. A rear extension (double storey) runs nearer 20 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 Newham 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 Newham average of £402,000, that's roughly £52,300 to £96,500 of capital uplift. Final return depends on the local market, the type of buyer in Newham, and your extension's specification.
Can I live in my home during the extension build?
Most Newham families stay in their home during a rear extension or garage conversion — works are contained to one side of the house. Two-storey side extensions and hip-to-gable lofts are noisier: expect 4–6 weeks where one floor or the driveway side is out of action. Plan temporary kitchen arrangements and dust control for the noisy weeks.
At what price does moving stop making sense in Newham?
Starting from Newham's average £402,000 home with a 22 m² high-spec rear extension (single storey) (£108,537 all-in), the tipping line sits at roughly £1,332,000: 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 Newham?
On a typical Newham trade-up from £402,000 to £645,000 (a 60% step up), Stamp Duty Land Tax (SDLT) is £22,250 — an effective rate of 3.45%. 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 Newham in 2026?
A 22 m² rear extension (single storey) in Newham runs about £109,000 all-in at high specification, on outer London build rates of around £3,300/m². A 45 m² rear extension (double storey) comes to roughly £209,000. 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 Newham?
The statutory determination period for a householder application is 8 weeks. London Borough of Newham decided 63% of householder applications within 8 weeks in the year to September 2025 (MHCLG figures, excluding agreed extensions of time). About 77% of applications here were granted (MHCLG, Q3 2025). 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 Newham?
Many single-storey rear extensions fall under Permitted Development — no planning permission needed. Newham has Article 4 directions covering HMO conversion and some specific PD types. The borough has fewer conservation areas than the inner-west boroughs; householder extensions outside conservation areas largely retain PD rights. Newham has 9 conservation areas, including Forest Gate, Plashet Park, Manor Park, where PD rights are curtailed. Side extensions, large rear extensions and most wraparounds need full planning regardless. Check the London Borough of Newham planning portal first. Open the London Borough of Newham 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 Bexley would carry about £22,000 of stamp duty — £250 less than in Newham.

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 outer 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.