Cost of Single Storey Extension in Weymouth (2026)
If you're looking at single storey extension in Weymouth right now, you should be seeing quotes in the £1,710 to £3,040 range per m². That's based on current Dorset contractor rates and the wider UK market. Anything well outside those numbers is worth questioning before you sign.
About single storey extension in Weymouth
Weymouth is a small town of around 53,000 in Dorset. The housing is mostly period cottages, Edwardian villas and 1930s semi-detached housing alongside newer commuter developments. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like DT3, DT4 tend to be quicker jobs with standardised fittings. Local trade prices sit in the same ballpark as the UK average, with Dorset firms quoting close to national rates.
Bristol and Bath run hot. Step outside them and into Devon, Cornwall or rural Somerset and the supply thins out fast, especially for specialist trades like heat pumps or unvented cylinders. Lead times get longer the further west you go, and most firms will add travel if you're past the nearest big town.
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 Weymouth
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 Weymouth?
- Ground conditions and foundation depth
- Glazing ratio (bi-folds, roof lights)
- Kitchen refit included
- Structural steels and knock-through
- Planning permission vs PD
Weymouth vs the UK average
Weymouth sits in the building & construction market at a cost multiplier of 0.95× the UK national average. That puts Weymouth single storey extension prices at £1,710–£3,040 versus the UK average of £1,800–£3,200 per m².
Single Storey Extension cost calculator — Weymouth
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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 Weymouth?
Budget £1,710 to £3,040 per m² for single storey extension in Weymouth. Prices here are around 5% cheaper than the UK average. What moves a quote inside that range is mostly building contractor day rates in Dorset and the specific material list for your job.
How long does single storey extension take in Weymouth?
A straightforward single storey extension job in Weymouth 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 Weymouth?
A proper single storey extension quote in Weymouth 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 Weymouth than the UK average?
Single Storey Extension in Weymouth runs around 5% cheaper than the UK average. The UK-wide benchmark for this job is £1,800 to £3,200 per m²; Weymouth quotes tend to land between £1,710 and £3,040. Handy to know what the average actually looks like before you price round.
Do I need planning permission for single storey extension in Weymouth?
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 Dorset 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 Weymouth.