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 Coulsdon 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
- CR5 and CR8
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
How much does a garage conversion cost in Coulsdon?
What should you budget for a garage conversion in Coulsdon? Use the figures below as a starting point. Prices in London sit about 30% above the national guide, so the range here is £15,500–£36,500 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Coulsdon |
|---|---|---|
| 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 |
The main things that change the figure:
- 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’s included?
- 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
- Plastering, skirting and decoration-ready finish
- Building control inspections and completion certificate
Homes in London
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.
London Clay shrinks and swells with the seasons, and street trees close to houses can contribute to movement, which affects foundation design.
Whatever era your Coulsdon home dates from, we plan a garage conversion around how it is actually built rather than a one-size-fits-all specification.
Permissions for a garage conversion in Coulsdon
Homes in Coulsdon come under the regulations for England, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
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.
The four stages
We look at the job
First, someone visits your home in Coulsdon to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Quote in writing
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.
Dates and permissions
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Coulsdon property.
Finish and handover
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
How we work
Questions about a garage conversion in Coulsdon
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.
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.
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 I need building regulations approval?
A garage conversion needs building regulations approval because the space becomes a habitable room. Building control checks that the new wall in the door opening has proper foundations, that the floor has a damp-proof membrane and insulation, and that walls and ceiling meet insulation standards. Ventilation, fire safety and escape routes are also checked. In Scotland a building warrant is normally needed before work starts.
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.
Near Coulsdon
Our coverage in Coulsdon includes CR5 and CR8. We also travel to Purley, Banstead and Wallington, so neighbouring addresses are looked after on exactly the same terms as those in town.

