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.
From a first conversation about a garage conversion to the day the site is cleared, homeowners in Sunbury-on-Thames deal with us directly. We come out to measure up at no cost, explain the choices in plain terms and send a written quote. For context, comparable work in the South East usually falls within £13,500–£31,500 including VAT, and it is available across KT8, KT12, TW12 and TW15.
- Guide price
- £13,500–£31,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- KT8, KT12, TW12, TW15 and TW16
- Planning rules
- England
- Local area
- Surrey
- Survey
- Free, with a written quote
Garage conversions prices in Sunbury-on-Thames
To help you plan, we show what a garage conversion typically costs in Sunbury-on-Thames instead of holding figures back for a sales call. The range is £13,500–£31,500 with VAT, using rates in the South East that are about 12% above the national guide. A free survey then fixes your actual price.
| Type of job | What it usually involves | Guide in Sunbury-on-Thames |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £11,000–£20,000 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £15,500–£28,000 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £24,500–£50,000 |
Your price depends mostly on:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Heating method and ventilation for the new room
- Window and door choices and the level of finishes
What do you get?
- 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
- New internal door or opening into the house
- Electrics, heating and ventilation by qualified trades, with certificates
- Building control inspections and completion certificate
Local housing and a garage conversion
Surrey has many Victorian and Edwardian villas, interwar semis in the commuter towns near London, and Arts and Crafts houses with tile-hanging and tall chimneys. Bargate stone appears around Godalming, and large detached homes are common in Guildford, Woking, Weybridge and the Surrey Hills villages.
Mild and relatively dry, with clay soils in the north and Weald that can move in summer; mature trees near houses affect foundations.
For a garage conversion in Sunbury-on-Thames, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Planning and building rules in Sunbury-on-Thames
Planning law differs across the UK. For a home in Sunbury-on-Thames, it is the England rules below that count, and we check them with the council ahead of any quote.
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.
What happens after you get in touch?
Free site survey
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 garage conversion so the price reflects your home.
Your fixed price
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a garage conversion.
Dates and permissions
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Build and hand over
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.
How we work
Garage conversions in Sunbury-on-Thames: questions
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.
How long does a garage conversion take?
A straightforward integral garage conversion usually takes two to four weeks on site. Attached garages that need roof or wall upgrades, and conversions with a shower room, typically take four to six weeks. Detached garages turned into annexes can take longer. Before work starts, allow time for drawings and building control approval. We give you a clear programme with your written quote.
Do I need planning permission for a garage conversion?
Whether a garage conversion needs planning permission depends on the works, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, converting an integral or attached garage is often permitted development where changes are mostly internal, unless a planning condition has removed those rights, which is common on newer estates. We check what applies before quoting.
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.
How much will a garage conversion cost in Sunbury-on-Thames?
As a guide, expect to pay £13,500–£31,500 including VAT for a garage conversion in Sunbury-on-Thames. That range is adjusted for the South East, which runs about 12% 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.
Near Sunbury-on-Thames
We welcome enquiries from all KT8, KT12, TW12 and TW15 postcodes in Sunbury-on-Thames, plus Walton-on-Thames, West Molesey and Hampton. Each one gets the same survey at no charge and a written price fixed for the work described.