On this page
How Much Does a Garage Conversion Cost?
For an initial benchmark, Checkatrade’s published guide places a typical 16m² integral or attached garage conversion at £10,000–£20,000 plus VAT. Its estimates increase for detached garages and larger spaces. Actual quotations depend on the property, specification and location.
| Garage conversion type | Indicative cost before VAT |
|---|---|
| Integral or attached garage, approximately 16m² | £10,000–£20,000 |
| Detached garage | £15,000–£25,000 |
| Double garage, approximately 36m² | £20,500–£45,000 |
These published ranges provide a starting point for budgeting. They do not establish an equivalent specification for every project, so check the proposed work, finishes and exclusions before comparing them with a quotation.
A property assessment is needed to establish whether your garage can support the intended layout and what preparation it requires.
What Affects the Price of Converting a Garage?
The size of the garage matters, but its condition and intended use can have just as much influence on the budget.
Existing Walls, Roof and Floor
A sound, dry structure provides a better starting point than a garage needing substantial repairs. Roof defects, damp, unsuitable floors or structural problems may need attention before the interior work begins.
Floor levels also affect the design. Raising a garage floor to connect comfortably with the house can influence insulation details, thresholds and finished ceiling height.
Windows, Doors and Structural Openings
Replacing the garage door with a wall and window changes both the exterior and the internal layout. The cost depends on the opening, support required, materials and how closely the finish needs to match the house.
Creating a new connection to an adjoining room may involve additional structural work. This should be assessed before the layout and budget are finalised.
Heating, Electrics and Plumbing
The position and capacity of existing services affect installation costs. A room needing lighting, sockets and heating has a different scope from one requiring water supplies, waste pipes and drainage.
Deciding where appliances, furniture and fitted units will sit early in the process helps establish the work accurately.
How Does the New Room Affect Your Budget?
The intended use determines the fittings, services and level of finishing required.
Home Office, Bedroom or Living Room
These conversions generally focus on creating a comfortable room with suitable insulation, lighting, heating and access.
A garage-to-home-office conversion may also need data connections, fitted desks or storage. A garage-to-bedroom conversion requires a layout suited to sleeping, furniture and privacy. Adding an en suite introduces a separate set of plumbing and fitting costs.
Kitchen or Utility Room
Kitchen and utility conversions need a more detailed specification. Cabinetry, worktops, appliances, plumbing and ventilation should all be included in the budget.
Compare the building work separately from the kitchen or utility fit-out. This makes it easier to see how changing the fittings affects the total without overlooking the underlying construction costs.
Annexe Accommodation
An annexe can involve several functions within one project, including sleeping, cooking and washing facilities. Independent access and connections to services may also affect the design.
Because the scope varies considerably, an annexe needs its own assessment rather than a price based on a standard single-room conversion.
Is a Partial Garage Conversion Cheaper?
Converting part of a garage can reduce the amount of space that needs finishing. It may suit homeowners who want a new room while retaining storage for bikes, tools or household equipment.
However, the price does not fall directly in proportion to the floor area. The project may still need electrical work, heating, a new window and a carefully constructed dividing wall.
Compare a partial and full conversion against the room you actually need. Keeping a little more storage is useful only if the finished room remains large enough to work comfortably.
What Should a Garage Conversion Quote Include?
A clear quotation should describe the completed result and the work needed to achieve it.
Look for details covering:
- Preparation, removals and waste disposal.
- Structural work and any supporting calculations.
- Floor, wall and roof upgrades.
- Windows, external doors and internal access.
- Electrical, heating, plumbing and ventilation work.
- Plastering, joinery, flooring and decoration.
- Drawings, applications and inspection fees where included.
- VAT, exclusions and provisional allowances.
Check what “finished” means. A quotation may include plastered walls but exclude painting, flooring or fitted furniture. These differences can make an apparently cheaper quote more expensive once the remaining work is added.
How Can You Keep the Project Within Budget?
Agree the room’s purpose and main layout before choosing decorative finishes. Moving a doorway or adding drainage after work starts can affect several trades and materials.
Separate essential work from optional features. The structure, comfort and practical layout should guide the budget first. Bespoke cabinetry, premium flooring and decorative lighting can then be considered against the amount remaining.
Keep a contingency for issues that cannot be confirmed until construction is opened up. Ask which parts of the quotation are fixed and which depend on further investigation, rather than assuming every item has the same level of certainty.
Get a Quote for Your Garage Conversion
The most useful price is one based on your garage and the way you want to use it.
Share your property location, approximate garage dimensions and preferred room type. Photographs and any existing plans can also help explain the starting point.
Explore our garage conversion options, then request a quote from Convert Garages to understand the proposed work, specification and budget for your home.