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
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 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.
Adjust the inputs to see your scenario. The page updates instantly as you adjust the inputs.
Moving is £64,582 cheaper than extending
Total: £43,955
Rear extension (single storey) — high spec
Total: £108,537
An extension of this type and size could add roughly £52,260 (≈13%) to your home's value — Nationwide Building Society, October 2025.
Where moving starts costing more than the extension you selected. The chart follows your inputs above.
Up to about £1,332,000 of target price, moving is the cheaper route in Newham; beyond that line, extending wins.
Decision speed: MHCLG householder statistics, year ending September 2025, excluding agreed extensions of time.
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 |
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 |
"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."
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.
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.