A loft conversion turns unused roof space into a habitable room such as a bedroom, bathroom or office, with a proper staircase, insulation, fire protection and natural light from rooflights or a dormer.
From Brent, Islington, Westminster and Bexley to the quieter corners of London, homeowners can book a free survey for a loft conversion. We look at the building, agree the scope, then send a quote in writing that fixes the cost of that scope. Work follows the rules for England, and our published range for London, £39,000–£84,000 with VAT, gives you a sense of budget before we visit.
- Guide price
- £39,000–£84,000 inc VAT
- Time on site
- 6–10 weeks on site
- Planning rules
- England
- Price level
- About 30% above the national guide
- Towns listed
- 90
- Survey
- Free, with a written quote
Loft conversions prices in London
No two jobs cost exactly the same, but the ranges below give a fair picture of a loft conversion in London. Pricing for London runs about 30% above the national guide, and the overall guide is £39,000–£84,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in London |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £26,000–£45,500 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £41,500–£78,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £65,000–£110,000 |
What moves the price up or down:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Adding a shower room or en-suite in the roof
- Staircase layout, fire doors and the level of finishes
What do you get?
- Structural calculations and steel beams where needed
- New floor joists strong enough for a habitable room
- Dormer, hip-to-gable or rooflight structure as agreed
- Staircase designed to fit your landing and meet regulations
- Insulation to walls, roof slope and floor
- Fire doors, mains-linked smoke alarms and a protected escape route
Housing across London
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
Terraces suit side-return extensions and rear dormer loft conversions; interwar semis commonly take hip-to-gable lofts. Shared party walls, restricted parking and conservation rules often shape the plans and the programme.
London Clay shrinks and swells with the seasons, and street trees close to houses can contribute to movement, which affects foundation design.
Do you need permission in London?
Planning law differs across the UK. For a home in London, it is the England rules below that count, and we check them with the council ahead of any quote.
In England, many loft conversions are permitted development: up to 40 m³ of extra roof space on a terraced house and 50 m³ on a semi-detached or detached house, no dormer on the front roof slope facing a road, nothing higher than the existing roof, and similar-looking materials. Conservation areas, listed buildings and flats need planning permission.
Building Regulations approval is always needed for a loft conversion: floor strength, a proper staircase, insulation, fire-protected escape route and smoke alarms. The Party Wall etc. Act 1996 usually applies on attached houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
Survey and measure
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a loft conversion, and photograph or measure anything the quote needs to reflect.
Written quote
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Plan and prepare
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
The work itself
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Questions about a loft conversion in London
Can you combine a loft conversion with other work?
Yes. Because we manage several trades under one contract, we can plan a loft conversion alongside other work on your London home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Do I need planning permission in London?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. London is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Does the Party Wall Act apply to a loft conversion?
The Party Wall etc. Act 1996 applies in England and Wales only, and loft conversions on terraced and semi-detached houses often fall within it, because steel beams are usually set into the shared wall. You must serve notice on the neighbour before work starts, and they can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act. We tell you during the survey whether notices are likely.
Can we stay at home during a loft conversion?
Most people stay at home during a loft conversion, because much of the work happens from scaffolding outside and the roof is opened up from above. The most disruptive point is near the end, when we break through the ceiling to fit the new staircase, which usually takes a few days. We put up dust screens on the landing and plan noisy work for reasonable hours.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £39,000–£84,000. A simple rooflight conversion costs less, while hip-to-gable and mansard conversions cost more because they change the roof structure. As a rough guide, allow around £800–£1,700 per square metre of new floor plus fixed costs for the staircase, steels and fees. Adding a shower room is the most common extra. We confirm a fixed price after surveying your loft.
Towns in London
We offer a loft conversion in each of the towns below, all within London. Select yours for guide prices, postcodes covered and nearby places.
- Acton
- Archway
- Barking
- Barnes
- Barnet
- Battersea
- Beckenham
- Becontree
- Bexley
- Blackheath
- Blackwall
- Bow
- Brent
- Brixton
- Camden Town
- Canary Wharf
- Canning Town
- Carshalton
- Catford
- Chalk Farm
- Chelsea
- Chessington
- Chingford
- Chiswick
- Coulsdon
- Cricklewood
- Croydon
- Dagenham
- East Barnet
- Edmonton
- Eltham
- Enfield Town
- Feltham
- Finchley
- Fulham
- Golders Green
- Greenford
- Greenwich
- Hadley Wood
- Hampton
- Hanworth
- Harrow
- Hayes
- Heston
- Highbury
- Holloway
- Hook
- Hornchurch
- Hounslow
- Ilford
- Isleworth
- Islington
- Kilburn
- Leytonstone
- Mitcham
- Morden
- Muswell Hill
- New Malden
- Northolt
- Notting Hill
- Peckham
- Pimlico
- Pinner
- Purley
- Putney
- Richmond
- Romford
- Ruislip
- Shepherds Bush
- Soho
- South Croydon
- Southall
- Stamford Hill
- Stratford
- Streatham
- Surbiton
- Sutton
- Thamesmead
- Tottenham
- Uxbridge
- Wallington
- Walthamstow
- Wealdstone
- Welling
- Wembley
- Westminster
- Willesden
- Wimbledon
- Wood Green
- Woodford Green