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 handle a loft conversion as a managed project across Cornwall: one contract, one contact, and trades working to an agreed specification. Coverage includes Redruth, Falmouth, St Austell and Truro and their surroundings. In England the consent rules have their own details, which we check for you. Typical prices in the South West fall within £30,500–£66,000, VAT included, and are fixed in writing after a survey.
- Guide price
- £30,500–£66,000 inc VAT
- Time on site
- 6–10 weeks on site
- Planning rules
- England
- Price level
- About 2% above the national guide
- Towns listed
- 7
- Survey
- Free, with a written quote
Loft conversions prices in Cornwall
Here is how the guide price for a loft conversion breaks down in Cornwall. We start from national figures and adjust for the South West, which comes out about 2% above the national guide. The resulting range, VAT included, is £30,500–£66,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Cornwall |
|---|---|---|
| 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 |
Your price depends mostly on:
- 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
- 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
- Staircase designed to fit your landing and meet regulations
- Insulation to walls, roof slope and floor
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
Homes in Cornwall
Older Cornish homes are often built of granite or slatey local stone, with slate roofs and sometimes slate-hung walls facing the weather. Cob cottages survive in places, Truro and Falmouth keep Georgian and Victorian streets, and many towns have rendered post-war houses, bungalows and newer estates on their edges.
Stone and cob properties often need breathable lime render, careful repointing and roof repairs. Post-war and newer homes commonly benefit from new windows, roofline renewal, external rendering and single-storey extensions.
Cornwall faces Atlantic gales, driving rain and salt-laden air, so render, pointing and window hardware on exposed elevations need a suitably robust specification.
Do you need permission in Cornwall?
Cornwall is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we 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.
How does the job run?
We look at the job
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a loft conversion so the price reflects your home.
Price and scope agreed
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Getting ready
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a loft conversion are in place before the first day on site.
The work itself
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
Frequently asked questions
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.
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 you cover Redruth, Falmouth and St Austell?
Yes. As well as Cornwall, we cover Redruth, Falmouth and St Austell and the rest of Cornwall. 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.
Can I put a bathroom in my loft?
A bathroom or shower room can usually be added in a loft conversion if waste pipes can reach the soil stack with enough fall, or a pumped system can be used. Dormers make this easier because they give standing height for a shower. Water pressure, extraction and the position of the boiler also matter. We plan the bathroom layout at the design stage so pipes are hidden in the structure.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Towns in Cornwall
Choose your town from the list to see how we price and plan a loft conversion in your part of Cornwall, including typical time on site.