How much does a garage conversion cost in the UK?

Updated 19 October 2026 · Reviewed by Steve Wolfe

A garage conversion in the UK typically costs £12,000 to £24,000 including VAT for a single integral or attached garage of about 16 m², or about £750 to £1,500 per square metre. A detached garage costs more because services have to be run to it, and a double garage £25,000 to £54,000.

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Typical costs

Typical UK prices including VAT, for a single garage of about 16 m² turned into a basic finished room, unless stated.

Type	Typical cost
Integral garage £12,000–£17,000 Built into the house, so services are close and only the door opening needs filling. Usually the cheapest. On site: 2 to 4 weeks	£12,000–£17,000
Attached garage £12,000–£24,000 Joined to the side of the house. May need a new doorway through to the house.	£12,000–£24,000
Detached garage £18,000–£30,000 Separate from the house, so electrics, water and heating have to be run out to it.	£18,000–£30,000
Double garage, about 36 m² £25,000–£54,000 From an integral double at the bottom of the range to a detached double at the top.	£25,000–£54,000
Partial conversion £6,500–£10,500 The front kept as storage, with a room or utility built behind it.	£6,500–£10,500

Our reading of the published guides listed under Sources, rounded and including VAT. Adding a bathroom or kitchen, moving the meter box or cutting a new doorway costs more.

What changes the price

Integral, attached or detached. An integral garage is already part of the house, with services close by. A detached one needs electrics, water and heating run out to it, which adds thousands.
The floor. Garage floors are usually lower and colder than the house. Most conversions add insulation and a new screed, and damp or an uneven slab adds more.
The door opening. Filling the old garage door with a wall and a window is part of nearly every conversion. A new doorway through to the house, or extra windows, costs more.
Heating and electrics. A radiator on the existing central heating is the usual choice if the boiler can take it. Otherwise it's electric heating or underfloor heating.
What the room is for. A bedroom, office or playroom is the cheapest. A bathroom, shower room or kitchen adds plumbing and drainage.
Hidden costs. Moving a gas or electricity meter, a weak flat roof or poor foundations under the old door opening only come to light once work starts.

Garage conversion or extension?

A garage conversion is one of the cheapest ways to add a room, because the walls, roof and foundations already exist. Per square metre it often costs less than half as much as a single-storey extension. The catch is losing the parking and storage, and on some estates converting the garage needs planning permission.

Before you get quotes

Check your deeds and the planning history for any condition about keeping the garage for parking.
Decide what the room is for, and whether it needs a bathroom, kitchen or new doorway.
Ask each builder whether building regulations fees, the door infill, heating, electrics, flooring and decorating are included. The FMB puts a building notice for a simple conversion at about £200.
If the garage shares a wall with a neighbour, you may need a party wall agreement. The FMB says these often start at about £700 per neighbour.
Get two or three quotes for the same specification.

An example Ballpark

What Ballpark gave for this job on 16 October 2026. It’s an example we worked out, not a customer’s price.

Convert an attached single garage in Birmingham into a playroom. Brick up the garage door with a window, insulate the floor, walls and ceiling, plaster, add a radiator and sockets.

Basic conversion £9,000–£13,500

Block up the door with a window, insulate, board and skim, a few sockets and an electric panel heater.
Full conversion as describedClosest to the job £13,000–£20,000

Bricked-up door with window, insulated floor, walls and ceiling, plastering, radiator on the central heating, sockets and lighting.
Higher-spec conversion £19,000–£28,000

As described plus underfloor heating, extra windows or a rooflight, new flooring, decorating and spotlights.

Based on

Single garage, about 3 m by 5.5 m
No structural changes beyond the door opening
Boiler can supply an extra radiator
Building regulations fees included, no planning permission

What a trade will ask you

Have answers ready and your quotes (and your ballpark) will be closer to the real price.

Is the garage integral, attached or detached, and single or double?
What will the room be used for?
Is there already a door through to the house?
Will it need a bathroom, kitchen or utility?
Can your boiler take another radiator, or would you prefer another kind of heating?
What condition is it in now? Any damp, a flat roof, or a meter box on the wall?

Common questions

Do I need planning permission to convert my garage?

Often not. Many garage conversions are permitted development because the work is mostly inside an existing building. But some newer estates have a planning condition that keeps garages for parking, and listed buildings and some conservation areas have tighter rules, so check with your council first. Every conversion needs building regulations approval.

Is it cheaper to convert a garage or build an extension?

Converting a garage is usually much cheaper per square metre: about £750 to £1,500 including VAT, against about £2,200 to £4,000 for a single-storey extension. The walls, roof and foundations are already there. The trade-off is losing the parking or storage.

How long does a garage conversion take?

Usually 1 to 4 weeks on site for a single garage, depending on its condition and how much work it needs.

Can I convert a garage myself?

Some people do the labour themselves. Checkatrade puts a DIY conversion at about £4,500 to £10,000 before VAT. It still has to meet building regulations and be signed off by building control, and electrical, gas and heating work should be done by qualified trades.

Are your prices including VAT?

Yes. Every price on this page includes VAT. Many guides quote garage conversion prices before VAT, so check which you're comparing.

What would yours cost?

Describe your garage conversion and get a ballpark for your house in a couple of minutes. Free, and you don’t have to get quotes.

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Sources

Checkatrade, garage conversion cost (May 2026). Costs by garage type before VAT, per m², what's included and timescales
Federation of Master Builders, garage conversion costs (Feb 2026). Typical cost for a 16 m² garage, day rates, building notice and party wall costs, from a member firm
HomeBuilding & Renovating, garage conversion costs (Apr 2025). Costs by garage type with a quantity surveyor

How we work out a ballpark