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.
If you have a garage conversion on your list for a property in Sevenoaks, we can help from the first measurements to the final clean-up. For a typical home, plan for 2–6 weeks on site, though larger or more complex jobs take longer. We cover postcodes TN13 and nearby Tonbridge, Swanley and Tunbridge Wells, and every quote we send is fixed for the scope described in it.
- Guide price
- £13,500–£31,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- TN13
- Planning rules
- England
- Local area
- Kent
- Survey
- Free, with a written quote
What should you budget for a garage conversion in Sevenoaks?
Prices for a garage conversion vary from house to house, but in Sevenoaks most projects fall within £13,500–£31,500 including VAT. That reflects costs in the South East, about 12% above the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Sevenoaks |
|---|---|---|
| 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 |
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 do you get?
- Infilling the garage door opening with insulated wall and new window
- 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
- Plastering, skirting and decoration-ready finish
- Building control inspections and completion certificate
Local housing and a garage conversion
Kent's older buildings include oast houses, weatherboarded cottages, Wealden timber-framed houses and Kentish ragstone walls. Medway towns have long rows of Victorian terraces, Margate and Ramsgate have Regency and Victorian seafronts, and Ashford, Maidstone and Dartford have seen large new estates alongside interwar and post-war housing.
One of England's sunnier, drier counties, but Thanet and the coast are windy, and Weald and London Clay soils can shrink in summer.
None of this holds for every street in Sevenoaks, which is why we look at your actual house before pricing a garage conversion rather than assuming from its age alone.
Planning and building rules in Sevenoaks
Which rules apply depends on where you live. For Sevenoaks, the answer is England, and the points below reflect that; we verify them with the council before quoting.
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?
Survey and measure
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.
Written quote
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.
Dates and permissions
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
On site to finish
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.
Why homeowners choose us
Questions about a garage conversion in Sevenoaks
How much will a garage conversion cost in Sevenoaks?
As a guide, expect to pay £13,500–£31,500 including VAT for a garage conversion in Sevenoaks. 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.
How much does a garage conversion cost?
A typical single garage conversion costs £13,500–£31,500, 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.
Do you cover Tonbridge, Swanley and Tunbridge Wells?
Yes. As well as Sevenoaks, we cover Tonbridge, Swanley and Tunbridge Wells and the rest of Kent. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
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 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.
Also covering areas around Sevenoaks
Homes across TN13 in Sevenoaks are within our coverage, as are those in Tonbridge, Swanley and Tunbridge Wells. If you are just outside these areas, ask anyway, because we work right across the UK.

