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.
Anyone planning a garage conversion in Hounslow wants three things: a clear price, a realistic timetable and a tidy job. We publish a guide of £15,500–£36,500 including VAT for London up front, explain that work normally takes 2–6 weeks on site, and confirm both in writing after a free survey of your property.
- Guide price
- £15,500–£36,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- TW3, TW4, TW5, TW7 and TW8
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
Garage conversions prices in Hounslow
Below is a breakdown of typical costs for a garage conversion in Hounslow. Because rates in London are about 30% above the national guide, the overall guide comes to £15,500–£36,500, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in Hounslow |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £13,000–£23,500 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £18,000–£32,500 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £28,500–£58,000 |
Expect these to shape the final quote:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Whether a shower room or kitchenette is included
- Heating method and ventilation for the new room
What does the job include in Hounslow?
- 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
- Electrics, heating and ventilation by qualified trades, with certificates
- Plastering, skirting and decoration-ready finish
- Building control inspections and completion certificate
Building in Hounslow
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
Terraces suit side-return extensions and rear dormer loft conversions; interwar semis commonly take hip-to-gable lofts. Shared party walls, restricted parking and conservation rules often shape the plans and the programme.
For a garage conversion in Hounslow, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Permissions for a garage conversion in Hounslow
Hounslow 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, 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
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a garage conversion, and photograph or measure anything the quote needs to reflect.
Price and scope agreed
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
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
Why homeowners choose us
Frequently asked questions
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.
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.
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a garage conversion, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
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.
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.
Also covering areas around Hounslow
Hounslow and its TW3, TW4, TW5 and TW7 postcodes are part of our coverage. Homeowners in Isleworth, Heston and Richmond can also book a free survey with us and receive a written price for their job.

