How Much Does Single-storey extension Cost in 2026?

Updated May 2026By TradeMatch Editorial TeamBuilder cost guide
Quick answer

Single-storey extension typically costs £30000 on average in the UK in 2026, ranging from £15000 for simple jobs to £50000 for complex installations. Final price depends on materials, location and access.

Low
£15,000

Simple jobs, off-peak, easy access

Average
£30,000

Most homeowners pay around this

High
£50,000

Complex jobs, premium materials, urgent

Prices reflect typical UK averages for builder work in 2026. London + South East adds ~20–40% premium. See full Builder cost guide →

What affects single-storey extension cost?

  • Location: London + South East run 20–40% above UK average; rural Wales, Scotland and Northern England 5–15% below.
  • Materials: premium brands, certified parts and warranties add 15–30% to the materials line.
  • Access: top-floor flats, listed buildings and limited-access properties take longer; reflect that in the labour quote.
  • Time of day: emergency / out-of-hours callouts add £80–£200; some builders charge a minimum-fee callout.
  • Vetting + insurance: Federation of Master Builders (FMB) / NHBC-registered builders often quote a few percent higher — but the work is insured, certified and resaleable.

Regional price variation

RegionTypical lowTypical averageTypical high
London + South East£18,000£39,000£70,000
Midlands + South West£15,000£30,000£50,000
North + Scotland + Wales£13,500£27,600£47,500

Single-storey extension cost FAQs

How much does single-storey extension cost in 2026?
Single-storey extension costs £15000–£50000 in the UK in 2026, averaging £30000. London adds 20–40% premium; rural areas often 10% lower. Get free, no-obligation quotes from vetted builders on TradeMatch to compare local prices.
What affects the cost of single-storey extension?
Materials quality, access difficulty, postcode, time of day (emergency callouts cost more), and whether parts need ordering all change the final price. Always get an itemised quote so you can see materials, labour and any callout fee separately.
Is it worth getting multiple quotes for single-storey extension?
Yes — quotes for the same job can vary 30–50% between tradespeople. TradeMatch shows up to 5 vetted builder quotes side-by-side so you can compare price, reviews and availability without phoning around.
How long does single-storey extension take?
Most builder jobs in this category take a few hours to a working day. Complex installations or repairs needing parts can extend to 2–3 days. A pre-quote site survey is the most reliable way to estimate exactly.
Do I need a vetted builder for this job?
Yes — using a Federation of Master Builders (FMB) / NHBC-recognised builder protects you from unsafe work, voided insurance and poor finishes. Every TradeMatch builder has been ID-checked, qualification-verified and insurance-checked.

Other builder jobs

Loft conversion

From £20000–£65000

Garage conversion

From £5000–£20000

Wall removal

From £500–£3000

Porch build

From £2000–£8000

All Builder costs

Hourly rates + every common job

Builder costs in top UK cities

Builder costs in LondonBuilder costs in BirminghamBuilder costs in ManchesterBuilder costs in LeedsBuilder costs in GlasgowBuilder costs in LiverpoolBuilder costs in NewcastleBuilder costs in Sheffield

Get free builder quotes for single-storey extension

Up to 5 vetted, insured builders — escrow-protected payment, verified reviews.

Post job free →