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.
Getting a loft conversion right in Coulsdon starts with understanding the house you already have: its age, how it was built and what has been altered over the years. We survey first, then commit on paper to a price that holds as long as the scope stays the same. Across London, guide prices run at £39,000–£84,000 including VAT, and homes in Purley, Banstead and Wallington are covered too.
- Guide price
- £39,000–£84,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- CR5 and CR8
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
What should you budget for a loft conversion in Coulsdon?
What should you budget for a loft conversion in Coulsdon? Use the figures below as a starting point. Prices in London sit about 30% above the national guide, so the range here is £39,000–£84,000 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Coulsdon |
|---|---|---|
| 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
- Steelwork and any strengthening of walls below
- Adding a shower room or en-suite in the roof
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
- Insulation to walls, roof slope and floor
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
Building in Coulsdon
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.
Knowing the typical building types in London helps, but a survey of your own home in Coulsdon is what decides the right approach to a loft conversion.
Planning and building rules in Coulsdon
For anyone in Coulsdon, the relevant framework is England's. The summary below is general, so we always contact the council about your address before putting a price in writing.
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.
Price and scope agreed
After the survey we send a quote for a loft conversion that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Dates and permissions
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
Finish and handover
Our trades complete a loft conversion while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
What you can expect from us
Questions about a loft conversion in Coulsdon
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 long will a loft conversion take?
On a typical home, allow 6–10 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
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.
Do I need planning permission in Coulsdon?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Coulsdon 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.
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.
Also covering areas around Coulsdon
We cover every part of Coulsdon, including CR5 and CR8, and nearby Purley, Banstead and Wallington. Wherever you are within that patch, the survey is free and the quote comes to you in writing.

