A garage conversion turns an integral or attached garage into a warm, habitable room by insulating the floor, walls and ceiling, replacing the garage door with a wall and window, and adding heating, lighting and finishes.
We handle a garage 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 £12,000–£28,500, VAT included, and are fixed in writing after a survey.
- Guide price
- £12,000–£28,500 inc VAT
- Time on site
- 2–6 weeks on site
- Planning rules
- England
- Price level
- About 2% above the national guide
- Towns listed
- 7
- Survey
- Free, with a written quote
How much does a garage conversion cost in Cornwall?
These are guide costs, not quotes. For a garage conversion in Cornwall the range is £12,000–£28,500, VAT included, reflecting prices in the South West that are about 2% 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 Cornwall |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £10,000–£18,500 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £14,500–£25,500 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £22,500–£46,000 |
What moves the price up or down:
- Condition of the floor, walls, roof and foundations
- Whether a shower room or kitchenette is included
- Heating method and ventilation for the new room
- Window and door choices and the level of finishes
Scope of the work
- Foundation checks under the door opening and footings where needed
- Damp-proof membrane, insulated floor and screed or raised timber floor
- Insulated walls and ceiling built to building regulations
- New internal door or opening into the house
- Electrics, heating and ventilation by qualified trades, with certificates
- Building control inspections and completion certificate
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.
Planning and building rules in Cornwall
For anyone in Cornwall, 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, converting an attached or integral garage into a room usually needs no planning permission, unless a planning condition on your estate has removed permitted development rights (common on newer houses). Changing the garage door to a wall and window is generally fine.
Building Regulations approval is needed: foundations for the infill wall, a damp-proof course, insulation, ventilation and fire safety.
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
A free survey comes first. It gives us what we need to price a garage conversion properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Plan and prepare
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 garage conversion are in place before the first day on site.
The work itself
Our trades complete a garage 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 garage conversion in Cornwall
How much does a garage conversion cost?
A typical single garage conversion costs £12,000–£28,500, depending on whether the garage is integral, attached or detached and what the room is for. Integral garages usually cost least because the walls and roof are already sound. Adding a shower room, upgrading a flat roof or levelling a sloping floor adds cost. As a guide, allow roughly £550–£1,100 per square metre plus fixed costs. We confirm a fixed price after the survey.
Does the floor need raising?
Garage floors are usually lower than the house floor and slope towards the door for drainage. Most conversions raise the floor with a damp-proof membrane, insulation and either a screed or a timber floor, so it lines up with the house and removes the step. The final level depends on ceiling height and the door into the house. We measure both during the survey.
How much will a garage conversion cost in Cornwall?
As a guide, expect to pay £12,000–£28,500 including VAT for a garage conversion in Cornwall. That range is adjusted for the South West, which runs about 2% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
How long will a garage conversion take?
On a typical home, allow 2–6 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.
Will the new room be warm enough?
A converted garage can be as warm as any other room in the house, provided the floor, walls and ceiling are insulated to current standards. Garages are usually built with single-skin walls and no insulation, so this work matters. Heating can come from a new radiator on your existing system, underfloor heating or an electric heater, depending on your boiler capacity. We advise on the most suitable option.
Towns in Cornwall
Looking for a garage conversion somewhere in Cornwall? Start with the towns below; each links to a page with pricing for your region and coverage details.