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.
Addresses across BS15 and BS16 fall within our coverage for a loft conversion, so if your home is in Mangotsfield we can arrange a survey on a day that works for you. We inspect the existing building, discuss materials and layout, and then price the agreed specification in writing. Expect a guide range of £30,500–£66,000 including VAT before that visit.
- Guide price
- £30,500–£66,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- BS15 and BS16
- Planning rules
- England
- Local area
- South Gloucestershire
- Survey
- Free, with a written quote
How much does a loft conversion cost in Mangotsfield?
The table below shows guide prices for a loft conversion in Mangotsfield. They are based on rates in the South West, which run about 2% above the national guide, giving an overall range of £30,500–£66,000. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Mangotsfield |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £20,500–£35,500 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £32,500–£61,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £51,000–£87,000 |
The main things that change the figure:
- 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
What does the job include in Mangotsfield?
- 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
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
What are homes like around Mangotsfield?
Golden Cotswold limestone defines towns and villages such as Cirencester, Stow and Tetbury, often with stone-slate roofs. Cheltenham is known for Regency stucco terraces and villas, Gloucester has Victorian brick terraces and interwar estates, the Stroud valleys have mill-era stone cottages, and the Forest of Dean uses its own sandstone.
Cotswold stone homes often need lime pointing, stone repairs and windows that suit conservation areas. Regency houses may call for render and decorating, while brick terraces and estate homes suit loft rooms and extensions.
Knowing the typical building types in Gloucestershire helps, but a survey of your own home in Mangotsfield is what decides the right approach to a loft conversion.
Planning and building rules in Mangotsfield
Planning law differs across the UK. For a home in Mangotsfield, 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.
What happens after you get in touch?
We look at the job
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a loft conversion.
Quote in writing
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
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.
On site to finish
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Why homeowners choose us
Frequently asked questions
Where will the new staircase go?
The new staircase usually sits above the existing stairs, rising from the landing so it uses space that is already circulation. Sometimes it needs to come from a small bedroom or box room, which reduces that room's size. Building regulations set rules on headroom, step size and handrails, with some flexibility for lofts. We look at options at the survey and show you how each affects the floor below.
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.
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.
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
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 Mangotsfield 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.
Nearby towns
Mangotsfield and its BS15 and BS16 postcodes are part of our coverage. Homeowners in Kingswood, Keynsham and Yate can also book a free survey with us and receive a written price for their job.

