How Much Does a Garage Conversion Cost in the UK? 2026 Prices by Use

A standard single garage conversion (about 15m², one new window, standard finish) costs £20,000 to £23,000 including VAT, drawings and Building Regulations at West Midlands rates, which works out at roughly £1,410 per m². The same job runs £18,250 to £21,750 in the North East and £26,000 to £32,500 in inner London. A double garage turned into an annexe with a bathroom and kitchen comes to £33,000 to £38,000. Every figure on this page comes straight from Quoteio’s calculator.

What does a garage conversion cost for each use?

The shell is the same whatever the room becomes: insulate and screed the floor, line and insulate the walls, build a new front wall where the door was, plaster, and run electrics and heating. What changes the price is what goes inside. Here is how the main options compare for a single garage of 5m by 3m at standard spec, and a double garage of 5.5m by 5m:

Standard spec, West Midlands rates, including drawings, Building Regulations and 20% VAT. Excludes furniture, kitchen appliances and decorating.

A bedroom and an office cost almost the same, because the difference is a few extra sockets and a data point. The big jumps come from water: an en-suite adds sanitaryware, tiling and a waste connection, and a kitchen adds units and worktops on top of that. The double garage annexe is the most expensive option here, but it creates a self-contained space that a single room can’t.

Where does the money go?

This is the engine’s breakdown for the standard single garage conversion, before fees and VAT. The largest line is labour, followed by electrics and plumbing, which carry a fixed set-up cost whatever the size of the room.

The headline range of £20,000 to £23,000 sits either side of the total above, because no two garages are identical. How we set the range.

How much does the finish level change the price?

Less than you might think. Going from standard to high spec on a single garage moves the price from £20,000 to £23,000 to £23,000 to £26,500. Most of a garage conversion is fixed work (the floor, the front wall, the insulation Building Control requires), so better linings, a bigger window and higher drawing fees add a modest amount compared with an extension, where spec changes the walls and roof too.

• Standard: £20,000 to £23,000. Plain plasterboard linings, a 1.2m white uPVC window.
• Mid-range: £21,000 to £24,500. Better wall linings, a wider window, more detailed drawings.
• High-end: £23,000 to £26,500. Premium linings, a 2.4m window, full architectural drawings.

Do I need planning permission for a garage conversion?

Usually not. Converting an attached or integral garage into a room is, in most cases, internal work covered by permitted development, provided you don’t extend the building or change its use to a separate dwelling. Quoteio’s garage estimates therefore include drawings and Building Regulations, but no planning fee.

There are exceptions worth checking before you spend anything:

• Newer estates. Some planning permissions for estates built in the last few decades remove permitted development rights or require garages to stay as parking. Your council’s planning register will show it.
• Conservation areas and listed buildings. Changes to the front of the house, including swapping the garage door for a wall and window, may need consent.
• Detached garages. Turning a detached garage into a bedroom or annexe is treated differently from an integral one, and creating a separate home usually needs full planning.

If you want written certainty, a lawful development certificate confirms the work is permitted. Building Regulations approval is needed in almost every case where the garage becomes a habitable room: Building Control will typically look at floor and wall insulation, damp proofing at the new front wall, fire escape, ventilation and electrical safety.

How do garage conversion prices vary across the UK?

Labour and materials cost more in London and the South East and less in the North East, Wales and Northern Ireland. Here is the standard single garage conversion priced in every region:

A South East conversion comes in at £22,000 to £26,000, against £26,000 to £32,500 in inner London. For a closer figure, see the regional pages for London, the South East, the North West or the West Midlands, or enter your postcode in the calculator.

What isn’t included in the price?

The estimate covers the conversion itself. A few things sit outside it and are worth asking every builder about:

• Foundations under the door opening. Garage floors and the strip under the old door are sometimes too shallow for a new wall. A builder will check this on site.
• Raising the floor. Many garage floors sit lower than the house. Bringing them level adds to the screed and insulation.
• Heating capacity. If your boiler can’t take another radiator, you may need electric heating or a boiler upgrade.
• Drainage for a bathroom. If the nearest soil pipe is far away, a pumped macerator or new drain run adds cost.
• Storage you are losing. Bikes, tools and the freezer need a new home, which can mean a shed or a smaller store kept at the front.

Is a garage conversion better value than an extension?

Per square metre, usually yes. The walls, roof and slab already exist, so you skip the foundations and new roof that make up a large share of an extension. Compare the figures in our single storey extension guide or the wider UK extension cost guide. The catch is that you trade parking and storage for living space rather than adding to the house, so it suits homes where the garage is already used as a store. If you need more than one room, a loft room is the other common option to compare.

Whichever you choose, get at least three written quotes, check each one covers Building Regulations and drawings, and use Quoteio to sense-check the numbers for your postcode.

Common questions