How much does a loft conversion cost in the UK?
A loft conversion in the UK typically costs between 20,000 and 65,000 pounds depending on the type of conversion, the size of the loft, the specification of finishes, and where in the country the property is located. London and the South East tend to run 20 to 30 per cent higher than the Midlands and North.
The most common types and their approximate cost ranges are:
- Velux (rooflight) conversion -- 20,000 to 30,000 pounds. Roof windows fitted into the existing roof slope, no structural changes to the roofline. Best suited to lofts with good existing headroom.
- Rear dormer conversion -- 35,000 to 55,000 pounds. A flat-roof or pitched-roof dormer extends out from the rear slope, creating full standing headroom and a usable bedroom or office with en suite.
- Hip-to-gable conversion -- 40,000 to 60,000 pounds. The sloping hip end of the roof is rebuilt as a vertical gable wall, gaining significantly more floor area. Often combined with a rear dormer.
- Mansard conversion -- 50,000 to 70,000 pounds. The entire roof structure is rebuilt with a near-vertical rear wall and a flat top. Creates the most space but is also the most expensive and almost always requires planning permission.
What affects the price
Beyond the conversion type, several factors push costs up or down:
- Structural steelwork requirements (floor joists, purlins, ridge beams)
- Staircase design and location -- a bespoke staircase can add 3,000 to 5,000 pounds
- En suite bathroom specification (basic shower room vs full bathroom)
- Scaffolding, skip hire, and building control fees
- Dormer cladding material (tile-hung, lead, GRP, render)
Budget an additional 10 per cent contingency for unforeseen work such as upgrading existing floor joists, relocating a water tank, or remedial work to the roof timbers.
What this means for a quote
A loft conversion quote should itemise the structural work, insulation, staircase, plastering, electrics, plumbing (if en suite), building control fees, and scaffolding as separate line items. This makes it easier to compare quotes on a like-for-like basis. TailoredQuote helps contractors produce that level of breakdown so customers can see exactly what they are paying for.