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.
We take on a loft conversion throughout Hampton and the surrounding KT7, KT8, TW11 and TW12 postcodes, as well as in West Molesey, East Molesey and Hanworth. The guide range for this work in London is £39,000–£84,000 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £39,000–£84,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- KT7, KT8, TW11, TW12 and TW13
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
How much does a loft conversion cost in Hampton?
These are guide costs, not quotes. For a loft conversion in Hampton the range is £39,000–£84,000, VAT included, reflecting prices in London that are about 30% above the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Hampton |
|---|---|---|
| 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 |
Expect these to shape the final quote:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Steelwork and any strengthening of walls below
- Staircase layout, fire doors and the level of finishes
Scope of the work
- 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
- Insulation to walls, roof slope and floor
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
Homes in 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.
None of this holds for every street in Hampton, which is why we look at your actual house before pricing a loft conversion rather than assuming from its age alone.
Permissions for a loft conversion in Hampton
England, Wales, Scotland and Northern Ireland each handle planning a little differently. Hampton comes under England, covered below, and we raise any questions with the council before your quote is finalised.
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.
The four stages
Free site survey
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.
Your fixed price
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a loft conversion.
Dates and permissions
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.
Finish and handover
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
Why homeowners choose us
Common questions
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.
Do you cover West Molesey, East Molesey and Hanworth?
Yes. As well as Hampton, we cover West Molesey, East Molesey and Hanworth and the rest of London. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Do I need planning permission for a loft conversion?
Whether a loft conversion needs planning permission depends on its size and design, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many conversions fall under permitted development if the added volume is within 40m³ for terraced houses or 50m³ for other houses and nothing extends beyond the front roof slope. We check what applies before quoting.
Is my loft suitable for conversion?
A loft is usually suitable for conversion if there is enough head height, a roof structure that can be adapted and space for a staircase. A common rule of thumb is at least 2.2m from the top of the ceiling joists to the underside of the ridge, though dormers and mansards can create height where it is short. Modern trussed roofs need more structural work. We check all of this at the survey.
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 Hampton 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.
Near Hampton
We survey and quote throughout Hampton's KT7, KT8, TW11 and TW12 postcodes and in surrounding places such as West Molesey, East Molesey and Hanworth. The process and pricing approach are identical in each of them.

