Building & Construction · Greater London

Cost of Single Storey Extension in Greenwich (2026)

Single Storey Extension in Greenwich works out at £2,195 to £3,905 per m² in 2025, give or take. Greenwich runs a bit over the UK average, which mostly comes down to Greater London labour rates and what the local housing stock demands. Straight like-for-like jobs hit the lower end; anything that needs pipework or structural changes pushes you up.

Typical cost in Greenwich +22%
Low £2,195
Typical £3,050
High £3,905
Typical price per m² Last updated 22 April 2026
  • FMB Federation of Master Builders
  • TrustMark Government-endorsed
  • FENSA Glazing installer scheme
  • NHBC Warranty-backed builds

About single storey extension in Greenwich

Greenwich is a large city of around 287,000 in Greater London. The housing is mostly South East London properties span Victorian terraces, post-war council estates and new-build apartment blocks. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like SE3, SE7, SE10 tend to be quicker jobs with standardised fittings. Local trade prices sit on the expensive side for UK trade work. That's mostly wage levels plus the cost of running a van and a yard in and around Greater London.

London's the deepest trade market in the country, and also the priciest. ULEZ, congestion charge, parking permits, higher van insurance — it all feeds into the day rate. Most decent firms charge a callout and central boroughs run a clear premium over zones 4 and 5. Book two to three weeks ahead if you can.

Building jobs are labour-heavy, and materials have moved fast — brick, timber, steel, insulation and board are all 20 to 40 percent up on pre-2022. FMB and TrustMark are your best signposts for a proper builder. On anything bigger than a loft conversion, get a Building Control officer involved from day one; fixing non-compliance later costs a fortune.

Single Storey Extension cost breakdown in Greenwich

Basic £2,195 – £2,685

Simple rear extension with standard finish

Standard £2,685 – £3,295

Open-plan kitchen extension with bi-fold doors

Complex £3,295 – £4,880

Wrap-around or glazed extension with lantern roof and structural steels

What affects the price of single storey extension in Greenwich?

  • Ground conditions and foundation depth
  • Glazing ratio (bi-folds, roof lights)
  • Kitchen refit included
  • Structural steels and knock-through
  • Planning permission vs PD

Greenwich vs the UK average

Greenwich sits in the building & construction market at a cost multiplier of 1.22× the UK national average. That puts Greenwich single storey extension prices at £2,195–£3,905 versus the UK average of £1,800–£3,200 per m².

Greenwich vs UK national average — per m² Greenwich £2,195 £3,905 UK average £1,800 £3,200
Typical price range, per m²

Single Storey Extension cost calculator — Greenwich

Estimated cost in Greenwich
£2,820 – £3,460
per m²

Estimate based on live 2025 UK trade pricing. Always get 3 written quotes before committing.

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What's typically included in a single storey extension quote

  • Foundations and drainage
  • Brick and block shell
  • Roof and glazing
  • First and second fix
  • Plaster and decoration

Frequently asked questions

How much does single storey extension cost in Greenwich?

Budget £2,195 to £3,905 per m² for single storey extension in Greenwich. Prices here are around 22% more expensive than the UK average. What moves a quote inside that range is mostly building contractor day rates in Greater London and the specific material list for your job.

How long does single storey extension take in Greenwich?

A straightforward single storey extension job in Greenwich runs to 10–16 weeks. You can lose days to things outside the contractor's control — parts on backorder, awkward access, or a firm slotting your job around existing bookings. Ask for a start date and expected finish up front.

What's included in the price of single storey extension in Greenwich?

A proper single storey extension quote in Greenwich should cover: Foundations and drainage; Brick and block shell; Roof and glazing; First and second fix; Plaster and decoration. If any of those aren't itemised on your quote, push back and ask. A written guarantee with a clear warranty period is reasonable to expect on this kind of work.

Is single storey extension cheaper in Greenwich than the UK average?

Single Storey Extension in Greenwich runs around 22% more expensive than the UK average. The UK-wide benchmark for this job is £1,800 to £3,200 per m²; Greenwich quotes tend to land between £2,195 and £3,905. Handy to know what the average actually looks like before you price round.

Do I need planning permission for single storey extension in Greenwich?

Most rear extensions fall under Permitted Development (up to 6m terraced/8m detached with Prior Approval). Side extensions and Article 4 areas require full planning. If the property sits in a conservation area or is listed, ring Greater London Council before you book anything in. It's a free call and saves a world of grief later.