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England

Rear extensions in Greater London

We design and build rear extensions across Greater London, from Islington and Bexley to Barking, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.

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Rear extension on a house typical of the area

What are homes in Greater London like to extend?

Much of Greater London is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.

Rear extension prices in Greater London

London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences. Per square metre including VAT, standard specification:

ExtensionPer m²
Single-storey rear extension£2,470–£4,030
Two-storey (per m² across both floors)£2,340–£3,510
Side return£2,990–£4,940
Wraparound£2,860–£4,680
Glass-led£3,640–£6,240

Planning and building rules in Greater London

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.

England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.

Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.

The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.

Rear extensions we build in Greater London

Towns and districts in Greater London

The main places we cover in Greater London include Islington, Bexley and Barking, across postcode areas BR, CR, DA, E, EC, EN, HA, IG, KT, N, NW, RM, SE, SM, SW, TW, UB and W.

Main towns in Greater London
TownPostcode districtsNearest town we also cover
IslingtonEC1R, EC1A, EC1VBarnsbury (0.7 miles)
BexleyDA5, DA6, DA14Sidcup (2.2 miles)
BarkingIG11, RM6, RM8Ilford (1.7 miles)
ArchwayN6, N19, NW5Crouch End (1.0 miles)
SuttonKT4, SM1, SM2Belmont (0.5 miles)
CroydonCR2, CR5, CR7Thornton Heath (1.1 miles)
IlfordE18, IG2, IG3Manor Park (1.2 miles)
Enfield TownEN1, EN2, N21Ponders End (1.7 miles)
HarrowHA1, HA2, HA3Harrow on the Hill (0.5 miles)
TottenhamN6, N8, N10Northumberland Park (0.4 miles)

Areas near Greater London

FAQ

Questions people ask

How much does a rear extension cost in Greater London?

As a guide, £2,470–£4,030 per square metre including VAT for a standard single-storey extension at London rates.

Do I need planning permission in Greater London?

Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.

Which towns in Greater London do you cover?

187 towns and districts, including Islington, Bexley and Barking.

Do you handle building control?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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