PRICE GUIDE · TRADES & CONSTRUCTION · 2026–2027
Loft Conversion cost in the UK
£30,000–£95,000 per project. Typically £42,000.
Loft conversions in the UK cost £30,000–£95,000, and a rear dormer — the most common type — is typically about £42,000. Roof shape and conversion type drive it: a roof-light conversion is cheapest, hip-to-gable and mansard conversions dearest, with an en-suite and London prices adding more.
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HOW MUCH IT COSTS
How much does loft conversion cost in the UK?
| Low end | £30,000 | a roof-light or simple rear dormer outside London |
|---|---|---|
| Typical | £42,000 | what most people pay |
| High end | £95,000 | a mansard with an en-suite, in London |
Locufy guide prices for 2026–2027. Updated 2026. A national range, not a quote — enter your town above for real prices from the builders and trades near you.
What moves the price
- Type of loft conversion — roof windows only cost least, then a rear dormer, hip-to-gable and mansard
- Head height — a loft without enough height may need the ceiling below lowered or the roof raised
- En-suite bathroom — plumbing, drainage and tiling in the loft add thousands to the conversion
- Stairs and fire safety — a new staircase, fire doors and a protected escape route are required
- Structural steel — beams and new floor joists are designed by an engineer and add to the cost
- London and terraced streets — access, party walls and higher labour rates make lofts there dearer
Building and repair prices in the UK are up 6% over five years (ONS Consumer Price Inflation, Services for maintenance and repair, to 2026 August). Five years ago a typical loft conversion would have cost about £47350 — an estimate from today's guide price and that index, not a recorded price. Source: ONS MM23 D7DO →
WHAT YOU GET
What a loft conversion booking includes
Takes: Six to twelve weeks on site for most loft conversions. Not included: Party wall surveyor fees, furniture, fitted wardrobes, decorating and any planning application fee are usually priced separately — see the related guides below.
WHAT PEOPLE BOOK
Common loft conversion jobs
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Loft Conversion near you, with prices shown
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How to pay less
- Choose a roof-light or rear dormer loft conversion rather than a mansard if the space works
- Place a loft en-suite above the existing bathroom so pipework and drainage runs stay short
- Check permitted development limits early so the loft is designed without a planning application
Before you book
- Every loft conversion needs building regulations approval for structure, insulation, stairs and fire safety
- Many dormer and roof-light lofts are permitted development, but mansards and front dormers usually need planning permission
- Serve party wall notices on attached neighbours before steel goes into a shared wall
- Ask a bat survey question early if the roof is old, as bats in a loft are protected
Loft Conversion cost: questions people ask
£30,000–£95,000 per project, about £42,000 typical for a rear dormer. A simple roof-light loft costs least; a mansard with an en-suite in London costs the most.
Six to twelve weeks on site for most homes, after design and approvals. A mansard or a loft with a bathroom takes longer.
Often not. A rear dormer within the permitted development volume limits can usually go ahead without it, but mansards, front dormers, flats and homes in conservation areas typically need permission. Building regulations approval is needed in every case.
Most lofts with enough head height under the ridge can be converted. Low roofs or trussed rafters make it harder and dearer, so get a survey first.
Party wall surveyor fees, furniture, fitted storage and decoration are generally extra.
They are Locufy guide prices for the UK, drawn up from published UK loft conversion cost guides — a national range, not a quote. The type of loft and your region set the real cost.