Quote check · September 2026
Is my loft conversion quote fair?
In September 2026 a rear dormer loft conversion of about 30 m² costs £56,500 to £69,500 including VAT to build in a typical home outside London, and £76,000 to £94,000 in London. Add design, a structural engineer, building control and a 15% contingency and a sensible all-in budget is £70,000 to £90,000. A quote inside the build range for your region, for the same scope of work, is a normal market price.
What loft conversions cost in 2026
These are the figures behind our calculator: a typical house, about 30 m² of new floor area and a mid-range finish. The build cost is what a builder's quote usually covers. The right-hand column is what you should budget in total.
| Loft type | Build cost, UK average | Build cost, London | All in, UK average, with fees and 15% contingency |
|---|---|---|---|
| Rooflight (Velux) | £32,500 to £42,000 | £43,500 to £56,500 | £42,500 to £58,500 |
| Rear dormer | £56,500 to £69,500 | £76,000 to £94,000 | £70,000 to £90,000 |
| Hip-to-gable (with rear dormer) | £66,000 to £81,500 | £89,000 to £110,000 | £81,000 to £104,000 |
| Mansard | £78,000 to £102,000 | £105,000 to £138,000 | £95,000 to £127,000 |
Rear dormer prices by region
The same dormer loft costs noticeably more in London and the South East than in the North, Wales or Northern Ireland, because labour costs more. Compare your quote with the row for where you live.
| Region | Build cost | All in with fees and 15% contingency |
|---|---|---|
| UK average (outside London) | £56,500 to £69,500 | £70,000 to £90,000 |
| London | £76,000 to £94,000 | £93,000 to £118,000 |
| South East | £65,000 to £80,000 | £80,000 to £102,000 |
| East of England | £60,500 to £74,500 | £74,500 to £95,500 |
| South West | £58,500 to £72,500 | £72,500 to £93,500 |
| West Midlands | £54,500 to £67,500 | £68,000 to £87,500 |
| East Midlands | £53,500 to £66,000 | £67,000 to £86,000 |
| Scotland | £53,500 to £66,000 | £67,000 to £86,000 |
| North West | £52,500 to £64,500 | £65,500 to £84,500 |
| Yorkshire and the Humber | £52,000 to £64,000 | £65,000 to £83,500 |
| Wales | £51,000 to £62,500 | £63,500 to £82,000 |
| North East | £49,500 to £61,000 | £62,500 to £80,500 |
| Northern Ireland | £46,000 to £57,000 | £58,500 to £75,500 |
First, check you are comparing the same thing
Plus VAT or including VAT? A quote of £65,000 plus VAT is £78,000 once VAT is added, so it is not cheaper than a quote of £70,000 including VAT. Put every quote on the same basis before you compare them.
What does the price cover? Two loft quotes can look close while covering very different amounts of work. These are the items most often left out or priced separately:
- The new staircase, and any changes to the landing or bedroom below it
- En-suite plumbing, tiling and the bathroom suite itself
- Electrics and lighting, including the mains-wired, linked smoke alarms Building Regulations expect
- Fire protection to the stairs and escape route
- Plastering, flooring and decorating
- Scaffolding, skips and making good the rooms below
- A party wall surveyor, if you share a wall with a neighbour
If one quote includes the stairs, the en-suite and the electrics and another does not, add a sensible allowance for the missing items before you decide which is cheaper.
Signs a loft quote is too high or too low
Possibly too high: well above the range for your region with no clear reason. Good reasons include a mansard or hip-to-gable design, steel beams, difficult access, a high specification or a very tight programme. Ask for an itemised breakdown and it will usually show you where the money goes.
Possibly too low: long lists of exclusions, large provisional sums for things like steelwork or structural work, no mention of building control or structural calculations, no written specification, or a request for cash or a large payment before work starts. Stage payments tied to finished work are normal.
Questions to ask before you sign
- Is the price fixed, and what could make it change?
- What exactly is excluded, and what are the provisional sums?
- Who arranges building control and the structural engineer?
- What is the payment schedule, and what has to be finished before each payment?
- Do you have public liability insurance, and do you offer a guarantee on the work?
- When can you start, and how long will the job take?
Check your own quote
Put your loft type, size and postcode into the loft conversion calculator to get the range for your area, then line your quotes up with our quote comparison worksheet. For fees, regulations and more detail, see the full loft conversion cost guide.