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.
Looking for a garage conversion in Wiltshire? We organise the whole job, bringing in the trades it needs under one agreement, and you have a single contact. We cover Swindon, Salisbury, Trowbridge and Chippenham, along with villages and suburbs nearby. The rules in England decide what consents are needed, and our guide range of £12,000–£28,500 including VAT gives you a realistic starting point for a budget.
- 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
- 5
- Survey
- Free, with a written quote
Garage conversions prices in Wiltshire
Budgeting for a garage conversion in Wiltshire? The numbers below include VAT and are adjusted for the South West, where costs are about 2% above the national guide. The headline range is £12,000–£28,500. Nothing is final until we have measured up at a free survey and agreed the specification with you.
| Type of job | What it usually involves | Guide in Wiltshire |
|---|---|---|
| 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 |
Your price depends mostly on:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Whether a shower room or kitchenette is included
- Window and door choices and the level of finishes
Scope of the work
- Infilling the garage door opening with insulated wall and new window
- 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
Homes in Wiltshire
Salisbury has medieval and Georgian streets, the north-west around Corsham and Bradford on Avon uses Bath stone, and chalk and flint appear on the downland. Swindon has railway-village terraces and very large post-war and modern estates, and many Wiltshire villages have thatched cottages, some with chalk cob walls.
Cob and Bath stone walls need breathable, lime-based repairs, and thatched cottages may need careful roof work. Swindon's railway terraces suit loft rooms and rear extensions, while its large estates often add garage conversions, driveways and landscaping.
Salisbury Plain and the downs are exposed to wind and frost, while river valleys around Salisbury and the Avon can flood.
Planning and building rules in Wiltshire
The notes below cover England, which is where Wiltshire sits. Rules change and every property is different, so we speak to the council before pricing your job.
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?
Free site survey
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Quote in writing
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
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.
Build and hand over
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.
What you can expect from us
Questions about a garage conversion in Wiltshire
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.
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.
Will losing the garage affect parking?
Losing a garage can matter if your street has parking pressure or your property deeds or planning conditions require off-street parking. Many garages are too narrow for modern cars, so in practice the driveway often provides the parking anyway. We check for planning conditions affecting the garage before quoting. If you need extra parking, we can also price a driveway extension.
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.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Towns in Wiltshire
These are the towns in Wiltshire where you can book a free survey for a garage conversion. Each has its own page with guide prices and coverage details.

