Verified Extension Builders in Southampton
Hire an identity-checked, insured extension builder in Southampton — with milestone-escrow payments that release only when you approve the work. Post your job free and compare quotes from trades within 50 miles.
Verified Southampton extension builders
Only identity- and insurance-checked extension builders can quote your job — no anonymous profiles, no cowboys.
Money held in escrow
Fund a milestone, approve the work, release the payment. Your money is protected at every stage.
Ranked on real outcomes
Trades carry an AxionOS Reputation Score built from completed, verified jobs — not fake reviews.
Hiring a extension builder in Southampton
Extension specialists build out or up — single- or double-storey, side-return and wrap-around. Most of the cost is groundworks, structure and the roof; kitchens or bathrooms inside are extra.
Whether it’s a small repair or a major project, AxionOS matches you with verified Southampton extension builders and protects the whole transaction. Describe the work — our AI Job Assistant turns a few words into a clear, quote-ready brief — then compare milestone-structured quotes and hire with confidence.
What a Southampton extension builder covers
- Single & double-storey extensions
- Side-return and wrap-around builds
- Foundations, walls and roofing
- Building-control sign-off
Extension builder cost in Southampton
Guide- Labour
- £8.6k–£32.4k
- Materials
- £9.7k–£36.5k
- Overhead & profit
- £3.2k–£12.2k
- Contingency (10%)
- £2.2k–£8.1k
+ £4.8k–£17.8k VAT if the trade is VAT-registered. Conservative national guide, adjusted for Southampton — verified Southampton extension builders quote a firm price for free.
Common questions
How much does a extension builder cost in Southampton?
A extension builder in Southampton typically works out around £23.8k–£89.1k (ex VAT, incl. a 10% contingency), driven by floor area (m²), number of storeys, glazing, and internal fit-out. That splits roughly into £8.6k–£32.4k labour and £9.7k–£36.5k materials. Southampton sits above the national average, so figures are adjusted for the area. It's a conservative guide — post your job free to get firm, itemised quotes.
Are the extension builders on AxionOS verified?
Yes. Every trade clears identity and insurance checks before they can quote, and carries a public reputation score built from completed, verified jobs.
How does payment work?
Funds sit in milestone escrow. The extension builder completes a stage, you approve it, and only then is payment released — no payout without your sign-off.