What a loft conversion costs in Birmingham
MyJobQuote's published figures put the average Birmingham loft conversion at around £41,000, from about £20,500 for a 30 square metre rooflight conversion to £70,000 for a mansard. The type of conversion moves the price most, then the size, the roof structure, an en-suite and the planning route. A written, itemised quote after a survey is the only figure to budget on.
Published Birmingham averages by type
These are MyJobQuote's figures for Birmingham, copied exactly from its page (updated 9 October 2026, checked by us 14 October 2026). They are a third party's estimates, not our prices, and they are useful for one thing: telling you whether a quote is in the normal range.
| Type | About 30 m² | About 50 m² | Weeks on site |
|---|---|---|---|
| Rooflight (Velux) | £20,500 to £31,000 | £26,000 to £41,000 | 4 to 6 |
| Dormer | £36,000 to £51,500 | £46,500 to £72,000 | 6 to 8 |
| Hip-to-gable | £46,500 to £61,500 | £56,500 to £72,000 | 6 to 8 |
| L-shaped dormer | £51,500 to £61,500 | £56,500 to £72,000 | not given |
| Mansard | £55,000 to £70,000 | £67,000 to £82,000 | 8 to 10 |
| Shell only (structure, no fit-out) | £20,500 to £41,000 | £31,000 to £56,500 | not given |
Source: MyJobQuote, Average cost of a loft conversion in Birmingham. Its overall timescale: 4 to 10 weeks, depending on the complexity of the job.
What moves the price
- The type of conversion
- Rooflight conversions change the roof least and cost least; mansards rebuild a whole slope and cost most. Dormers, L-shaped dormers and hip-to-gables sit between.
- Size
- More floor area means more structure, insulation, plasterboard and flooring. The published figures above step up between a 30 and a 50 square metre conversion for that reason.
- The roof structure
- A traditional cut roof can be opened up around its timbers. A trussed rafter roof, common from the 1960s, needs a new structure, usually steel, before the trusses come out.
- An en-suite
- A bathroom adds plumbing, drainage to the soil stack, tiling, extraction and fittings, and often a change to the hot water system when the loft tank goes.
- The planning route
- Permitted development with a Lawful Development Certificate is the cheaper route; a full planning application adds design work and fees, and in a conservation area may mean better-matched materials.
- The staircase and the floors below
- The new stair usually takes space on the landing; fire doors go on the habitable rooms off the stair on every floor. Where the stair takes part of a bedroom, there is more work below.
- Neighbours and access
- Party wall surveyors' fees where a neighbour appoints one, and scaffold and skip arrangements on terraces with no rear access.
How to compare quotes
Two quotes for the same loft can differ by a lot and still both be honest, because they include different things. Put them side by side and check each of these lines:
- Design, drawings and structural calculations: included, or charged separately?
- Planning application or Lawful Development Certificate, and Building Regulations fees.
- Party wall costs, including a surveyor if a neighbour appoints one.
- Scaffold, roof cover and skips for the whole job.
- The staircase, fire doors on the existing floors, and making good below.
- Windows and rooflights: number, size and type.
- Electrics, heating and, for an en-suite, sanitaryware and tiling.
- The finish: plastered and ready to decorate, or decorated with flooring laid.
- VAT, and what happens if something unexpected is found when the roof is opened.
If a line is missing from one quote, ask about it before choosing. Our process page shows what happens at each stage, and the planning guide explains which approvals your house is likely to need.
Questions people ask
How much does a loft conversion cost in Birmingham?
MyJobQuote puts the average at around £41,000 (updated 9 October 2026). Its published ranges for a 30 square metre conversion run from £20,500 for a rooflight conversion to £70,000 for a mansard. Your own price depends on the type, size, roof structure and finish.
What is the cheapest type of loft conversion?
A rooflight (Velux) conversion, because the roof keeps its shape. It is only possible where the loft already has enough height, about 2.2 metres under the ridge as a rule of thumb.
Does a loft conversion need VAT?
Building work on an existing house is normally standard-rated for VAT. When comparing quotes, check whether each one includes VAT so you are comparing like with like.
What should a loft conversion quote include?
The design and drawings, structural calculations, planning or Lawful Development Certificate fees, Building Regulations fees, party wall costs, scaffold and skips, the structure, the staircase, windows, insulation, electrics, plumbing, fire doors, plastering and the finish level. Ask for it itemised.
Get a price for your loft
Tell us about the house and the room you want. We will come back to you to arrange a survey, then send an itemised quote.