If you’re wondering how much a garage conversion costs in the UK, a realistic 2026 budget is usually around £8,000–£25,000, depending on the size and condition of the garage, the type of conversion, the specification and whether you need plumbing, structural work or higher-end finishes.
For a standard single integral or attached garage being converted into a comfortable habitable room, many homeowners should budget roughly £10,000–£20,000. A simple office or playroom can cost less, while a bedroom with an en-suite, premium finishes or extensive structural work can push the project above £20,000.
London and parts of the South East can be more expensive because labour and construction costs are generally higher.
This guide explains garage conversion costs in 2026, including prices by garage type, cost per square metre, different room types, hidden costs, planning permission, building regulations, project timescales and ways to control your budget.
Garage Conversion Cost at a Glance
| Garage conversion type | Typical 2026 cost |
| Basic single garage conversion | £8,000–£15,000 |
| Standard single garage conversion | £10,000–£20,000 |
| Integral garage conversion | £10,000–£18,000 |
| Attached garage conversion | £10,000–£20,000 |
| Double garage conversion | £15,000–£30,000 |
| Detached garage conversion | £15,000–£35,000 |
| Garage with bedroom | £12,000–£22,000 |
| Garage with en-suite | £18,000–£30,000+ |
| High-spec conversion/annexe | £25,000–£35,000+ |
These are indicative budgeting ranges rather than fixed quotations. The condition of the existing garage and the specification you choose can make a significant difference.
For comparison, current UK cost guides commonly place standard garage conversions around £10,000–£20,000, with higher costs for detached garages, double garages and projects involving plumbing or premium finishes.
Extra Reading: How Much Value Does a Loft Conversion Add?
Garage Conversion Cost Per m²
A useful way to compare garage conversion prices is to calculate the cost per square metre.
For a typical UK conversion, a reasonable 2026 budgeting range is approximately:
£700–£1,500 per m²
A basic conversion may fall closer to the lower end, while a bedroom with an en-suite, premium finishes or substantial services work can move towards the upper end.
| Conversion specification | Approx. cost per m² |
| Basic habitable room | £700–£1,000 |
| Standard bedroom/office | £1,000–£1,400 |
| Bedroom + en-suite | £1,400–£1,800 |
| High-spec/self-contained space | £1,500–£2,000+ |
For example, a 15m² garage converted into a standard habitable room could have a broad construction budget of approximately £10,500–£21,000, depending on specification and existing conditions.
Cost-per-m² figures should only be used as a budgeting guide. A small garage requiring expensive drainage or structural work can have a higher per-m² cost than a larger, straightforward conversion.
Single Garage Conversion Cost
A single garage conversion is one of the most common projects.
For a standard single garage, homeowners can typically budget around:
£8,000–£18,000
A basic conversion may include:
- Insulation
- Damp-proofing
- Garage door infill
- New window
- Electrical upgrades
- Heating
- Plastering
- Flooring
- Decoration
If you’re creating a bedroom, adding an en-suite or using premium finishes, the budget can increase significantly.
Current 2026 market guides place single-garage costs across a fairly wide range because the specification and condition of the garage vary considerably.
Double Garage Conversion Cost
A double garage conversion provides substantially more floor space and can create a large open-plan living area, two rooms, a bedroom suite or a self-contained space.
A typical 2026 budget is approximately:
£15,000–£30,000+
A double garage conversion can cost more than simply doubling the price of a single garage because larger spaces may require:
- Additional insulation
- More electrical points
- More heating
- Multiple windows
- Larger structural alterations
- More flooring and plastering
- Additional plumbing
- Higher-quality finishes
The final cost depends heavily on the proposed layout.
Integral Garage Conversion Cost
An integral garage forms part of the main house and normally shares walls, services and access with the property.
This can make it one of the more straightforward garage conversions.
Typical budget:
£10,000–£18,000
However, an integral garage still needs to be transformed into a properly insulated and compliant living space.
Typical work can include:
- Removing or infilling the garage door
- Installing a suitable insulated wall
- Upgrading the floor
- Adding wall and ceiling insulation
- Installing heating
- Upgrading electrics
- Adding windows where appropriate
- Plastering and decorating
- Installing flooring.
Detached Garage Conversion Cost
Detached garages can be more expensive because they are separated from the main house.
A typical budget may be:
£15,000–£35,000+
The additional cost can come from connecting:
- Electricity
- Water
- Heating
- Drainage
- Internet/data services
You may also need more extensive external work.
Planning requirements can also be more complicated depending on the intended use and proposed alterations, so check with your local planning authority before starting work.
Garage Conversion Cost by Room Type
What you intend to use the garage for has a major effect on the final price.
Garage to Bedroom Cost
Converting a garage into a bedroom can cost approximately:
£12,000–£22,000
The project may require:
- Better thermal insulation
- Heating
- Suitable ventilation
- New windows
- Electrical sockets
- Lighting
- Flooring
- Fire safety measures
- Appropriate escape arrangements
If you add an en-suite, plumbing and drainage can increase the budget considerably.
Garage Conversion Cost Breakdown
Understanding where your money goes makes it easier to compare quotations.
A typical project can include:
| Work | Indicative budget |
| Garage door infill/structural work | £1,500–£3,000 |
| Floor insulation/upgrading | £1,000–£2,500 |
| Wall/ceiling insulation | £1,000–£2,500 |
| Windows/doors | £1,000–£2,500 |
| Electrical work | £800–£2,000 |
| Heating | £500–£1,500 |
| Plumbing | £1,000–£4,000+ |
| Plastering | £800–£1,800 |
| Flooring | £500–£1,500 |
| Decoration | £500–£1,500 |
| Design/Building Control | £800–£2,000+ |
These figures overlap depending on the project, so they should not simply be added together as a quotation.
What Are the Hidden Costs of a Garage Conversion?
The biggest budget problems often come from work that wasn’t identified at the beginning.
1. Floor problems
Garage floors can be lower than the main house floor. You may need to raise or rebuild the floor to achieve the correct finished level.
2. Damp
A garage may not have been constructed to the same standard as a heated living space. Damp-proofing and moisture protection may therefore be necessary.
3. Insulation
A garage needs suitable thermal insulation if it is becoming a habitable room.
4. Garage door replacement
The existing garage door normally needs to be removed or redesigned as part of the conversion.
5. Drainage
Bathrooms and en-suites can require new drainage routes, which can become expensive if the nearest connection is far away or difficult to access.
6. Electrical upgrades
An old garage may have limited electrical provision compared with the main house.
7. Structural work
The garage door opening, walls, floor or foundations may require structural alterations.
8. External finishes
Replacing the garage door with a wall and window means the new elevation needs to match the existing property as closely as practical.
A proper site survey before construction can help identify these issues before they become expensive surprises.
How Long Does a Garage Conversion Take?
A straightforward garage conversion can often take around:
2–6 weeks
The exact programme depends on:
- Garage size
- Existing condition
- Structural work
- Plumbing
- Bathroom installation
- Design requirements
- Building Control inspections
- Material availability
- Level of finish
A simple office conversion may be considerably faster than a garage conversion involving an en-suite or extensive structural work.
It is sensible to allow additional time for design, approvals and procurement before construction starts.
Do You Need Planning Permission?
Most garage conversions fall under permitted development rights, meaning no formal planning application is needed. This applies when the work stays within the existing footprint and does not change the external appearance much.
You will still need building regulations approval, since this covers safety, insulation, and structural soundness. Check with your local council or the UK government planning portal before starting work, since rules vary slightly by region.
Why Work With ABL Design & Build
ABL Design & Build has handled garage conversions across London for years, working with families who want more space without the cost of moving. The team manages everything from initial design through to final sign-off, so you are not chasing separate trades yourself.
If your garage conversion needs extra headroom, We offer Loft conversions London services, giving you a second option if a garage alone will not create enough space for your household.
Extra Reading: How Long Does a Loft Conversion Take?
Final Thoughts
Understanding real Garage Conversion Cost figures helps you plan a project that fits your budget and your household needs. Get multiple quotes, ask for a per square metre breakdown, and factor in hidden fees before you commit. A garage conversion remains one of the most cost effective ways to gain extra space at home.
Ready to get started? Contact us today for a free, no obligation quote on your garage conversion project.
Garage Conversion Cost FAQs
How much does a garage conversion cost in the UK?
A typical 2026 garage conversion costs approximately £8,000–£25,000, with many standard single-garage projects falling around £10,000–£20,000.
How much does a single garage conversion cost?
A single garage conversion commonly costs around £8,000–£18,000, depending on the condition, size and specification.
How much does a double garage conversion cost?
A double garage conversion can cost approximately £15,000–£30,000+, depending on the layout and level of finish.
How much does a garage conversion cost per square metre?
A reasonable 2026 budgeting range is approximately £700–£1,500 per m², although high-specification projects can exceed this.
Do I need planning permission to convert my garage?
Planning permission is not usually required for internal garage conversions that do not enlarge the building, but restrictions can apply. Always check the property’s planning history and local requirements before starting work.
Do I need Building Regulations approval?
Yes, a garage converted into habitable space will normally require Building Regulations approval.
How long does a garage conversion take?
Most straightforward projects take around 2–6 weeks, although more complex conversions can take longer.
Is it cheaper to convert a garage or build an extension?
A garage conversion is normally cheaper because the main structure already exists. However, the best option depends on the condition of the garage and how much additional space you need.
Can I convert my garage into a bedroom?
Yes, provided the project meets the relevant Building Regulations and any planning requirements that apply to your property.
Can I add a bathroom to a garage conversion?
Yes. However, plumbing, drainage, ventilation and waterproofing can significantly increase the overall project cost.