Mazdurr
Verified builders, bidding for your project
A build is the job where paying up front hurts most, and where most disputes start. On Mazdurr the money sits with Stripe and moves stage by stage, released by you as the work actually happens.
What builders typically charge
Indicative UK ranges for a typical job, to help you sense check a quote. They are not a price from Mazdurr: the real number comes from trades bidding on your actual job.
| Job | Typical range | What moves the price |
|---|---|---|
| Single storey rear extension | £1,800 to £2,600 per m2 | A 20m2 extension typically lands between £36,000 and £52,000. |
| Loft conversion, rooms in roof | £25,000 to £45,000 | Dormer conversions sit at the upper end. |
| Knock through two rooms | £1,800 to £4,500 | Depends entirely on whether the wall is load bearing. |
| Garage conversion | £8,000 to £18,000 | Includes insulation, flooring and making it habitable. |
| Re-point a house | £1,200 to £3,500 | Scaffolding is often a separate line. |
| Underpinning, per metre | £1,500 to £2,500 | Always follows a structural engineer's report. |
Ranges reflect labour in most of the UK and exclude VAT where the trade is not registered. London and the South East usually sit at the top of each band. Materials are included only where stated.
What we check before a builder can bid
Verification happens once, before the first bid, not after something goes wrong.
Photo ID verified
Identity confirmed before any bid can be placed.
Public liability insurance
At least £1m of cover, certificate and expiry held on file.
Trade body membership
FMB, NFB or similar shown on the profile where held, so you can weigh it yourself.
Reviews tied to completed jobs
A review can only be left by someone who paid for a job through Mazdurr, so the score cannot be padded.
How bidding works
You describe the job once. They compete for it.
Describe the job
Add your postcode and photos. It takes about 90 seconds and costs nothing.
Bids arrive live
Verified builders bid against each other. You see the price, the rating and the profile.
Release stage by stage
Money is held by Stripe and released by you as the work is completed, not before.
Common questions
The things people ask before booking a builder.
How much does a single storey extension cost in the UK?
Budget roughly £1,800 to £2,600 per square metre for a standard single storey rear extension, so a 20 square metre extension usually lands between £36,000 and £52,000. London and the South East sit at the top of that band. The figure excludes kitchen units, bathroom suites and finishes, which are where budgets most often slip.
Should I pay a builder a deposit up front?
A builder ordering materials reasonably needs money before work starts, but handing over a large lump sum with no protection is how people lose thousands. On Mazdurr the payment is held by Stripe and released in stages that you approve, so the builder has certainty the money exists while you keep control of when it moves.
Do I need planning permission for an extension?
Many single storey rear extensions fall under permitted development, but the limits on depth, height and proximity to boundaries are strict, and they differ for terraced, semi-detached and detached homes. Conservation areas and listed buildings change everything. Check with your local planning authority before committing, and get a lawful development certificate if you are relying on permitted development.
What happens if the builder walks off the job?
You have only released the stages that were actually completed, so the unspent money is still yours rather than gone. You can then post the remaining work as a new job. This is the single biggest practical difference between Mazdurr and paying a builder directly.
Related trades
Jobs often need more than one trade. Post them together and compare bids side by side.