Cost of Single Storey Extension in Wandsworth (2026)
If you're looking at single storey extension in Wandsworth right now, you should be seeing quotes in the £2,340 to £4,160 range per m². That's based on current Greater London contractor rates and the wider UK market. Anything well outside those numbers is worth questioning before you sign.
About single storey extension in Wandsworth
Wandsworth is a large city of around 329,000 in Greater London. The housing is mostly South West London housing leans Victorian and Edwardian with pockets of 1930s semis and modern flats. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like SW8, SW11, SW15 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 Wandsworth
Simple rear extension with standard finish
Open-plan kitchen extension with bi-fold doors
Wrap-around or glazed extension with lantern roof and structural steels
What affects the price of single storey extension in Wandsworth?
- Ground conditions and foundation depth
- Glazing ratio (bi-folds, roof lights)
- Kitchen refit included
- Structural steels and knock-through
- Planning permission vs PD
Wandsworth vs the UK average
Wandsworth sits in the building & construction market at a cost multiplier of 1.30× the UK national average. That puts Wandsworth single storey extension prices at £2,340–£4,160 versus the UK average of £1,800–£3,200 per m².
Single Storey Extension cost calculator — Wandsworth
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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 Wandsworth?
Budget £2,340 to £4,160 per m² for single storey extension in Wandsworth. Prices here are around 30% 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 Wandsworth?
A straightforward single storey extension job in Wandsworth 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 Wandsworth?
A proper single storey extension quote in Wandsworth 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 Wandsworth than the UK average?
Single Storey Extension in Wandsworth runs around 30% more expensive than the UK average. The UK-wide benchmark for this job is £1,800 to £3,200 per m²; Wandsworth quotes tend to land between £2,340 and £4,160. Handy to know what the average actually looks like before you price round.
Do I need planning permission for single storey extension in Wandsworth?
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.
See all single storey extension prices across the UK or browse all tradespeople costs in Wandsworth.