Single Garage Conversion Cost Guide UK

Quick Cost Breakdown

• The average cost of a single garage conversion in the UK is £5,000 - £15,000, depending on the size, condition, and level of finish.
• For a higher-spec finish with new windows, heating, and plumbing, expect to pay £15,000+.
• The main cost factors are garage size, structural condition, type of room you're converting to, and whether planning permission is needed.

Your Single Garage Conversion Cost Guide

In this cost guide, we’ll cover:

1. Is Converting My Single Garage Worth The Cost?
2. Labour Costs for a Single Garage Conversion
3. Single Garage Conversion Cost by Room Type
4. Do You Need Planning Permission for a Single Garage Conversion?
5. Cost-Saving Tips for a Single Garage Conversion
6. Find Garage Conversion Specialists Near You on MyBuilder
7. FAQs: Common Questions About Single Garage Conversions

Is Converting My Single Garage Worth The Cost?

For most homeowners, a single garage conversion is one of the best home improvements they can make.

You're working with a structure that already has foundations, walls, and a roof, so the cost per square metre is far lower than building a house extension from scratch.

A typical single garage offers around 15m² of floor space, enough for a comfortable double bedroom, a home office with storage, or a self-contained playroom. Converting that space costs £5,000 - £15,000 on average, while adding an extension of the same size could set you back £25,000 - £50,000. A well-finished garage conversion can add 10 -15% to your property's value, particularly if it creates an extra bedroom.

Estate agents consistently rank garage conversions among the highest return-on-investment projects for UK homes. That said, it's not always the right move. If your area has limited on-street parking and the garage is your only off-road space, removing it could actually reduce your home's appeal to buyers.

The best way to find out exactly what your conversion will cost is to speak to a garage conversion specialist near you. It’s easy to find conversion specialists near you on MyBuilder.

Ask a conversion specialist

Labour Costs for a Single Garage Conversion

Labour typically makes up 40 - 50% of the total single garage conversion cost, so it's worth understanding where that money goes.

Most conversions need several trades working in sequence - and the more complex the project, the more hands involved.

The trades you may need to hire:

• Builder / bricklayer: Removes the garage door, builds the new front wall with a window opening, installs the lintel, and handles any structural alterations. See our new brick wall cost guide for more detail.

• Electrician: Runs new circuits from your consumer unit, installs sockets, light fittings, and switches. All work must comply with Part P of the Building Regulations.

• Plasterer: Skims the walls and ceiling once insulation boards and electrics are in place. A single garage typically needs 2 - 3 coats for a smooth, paint-ready finish. See the full guide on the cost of plastering.

• Plumber: Only needed if you're adding a bathroom, shower room, or kitchen area. First-fix pipework goes in before plastering, second-fix (fitting taps, toilets, sinks) comes after. See our plumber hourly rate guide for a full breakdown.

• Carpenter / joiner: Fits internal doors, skirting boards, architraves, and any built-in storage. If you're replacing the garage door with a glazed screen or bi-fold doors, a joiner may handle the installation.

• Decorator: The final trade on site - painting, wallpapering, and finishing touches.

Should You Hire a Main Contractor?

If managing multiple trades sounds like a headache, a main contractor or project manager can coordinate everything for you. They'll typically charge a 10 - 20% markup on top of the individual trade costs, but you get a single point of contact, a managed schedule, and less risk of gaps between trades.

Find a contractor near me

Single Garage Conversion Cost by Room Type

The type of room you're converting your garage into has the biggest impact on the final price. A simple dry room with electrics is a very different job to a fully plumbed en-suite bedroom or self-contained annexe.

Here's what each conversion typically costs:

Room Type	Typical Cost
Home Office	£5,000 - £9,000
Bedroom	£7,000 - £12,000
Bedroom + En-Suite	£12,000 - £18,000
Playroom / Family Room	£6,000 - £11,000
Home Gym	£5,000 - £8,000
Studio Annexe	£18,000 - £30,000

Home Office

The most straightforward conversion and the cheapest to get right. You'll need insulation, electricity (plenty of sockets and a dedicated data point if you work from home full-time), plastering, and flooring.

A new front wall with a large window keeps the space bright. Most home office conversions sit comfortably at £5,000–£9,000.

Bedroom

A step up from an office - you'll want better soundproofing, a radiator or panel heater, and potentially a higher insulation specification to keep the room comfortable year-round. A standard bedroom conversion runs to £7,000 - £12,000.

Add an en-suite shower room and you're looking at £12,000 - £18,000, with the plumbing and tiling accounting for most of the jump.

Playroom or Family Room

Families love this one. A heated, insulated space with durable flooring and plenty of natural light makes a brilliant playroom or extra living area.

Bi-fold or French doors replacing the garage door are popular here - they flood the room with light and open onto the garden in summer. Budget £6,000 - £11,000, with the doors sitting at the higher end of the range at £2,500 - £3,500 installed.

Home Gym

A garage gym needs less finish work than a bedroom but more thought around ventilation and flooring. Rubber gym flooring, reinforced wall mounts for equipment, and good airflow are the priorities.

At £5,000–£8,000, it's one of the more affordable conversions - and saves you a gym membership in the long run.

Studio Annexe

This is the premium option. A self-contained annexe with a bathroom, kitchenette, and separate entrance involves plumbing, drainage, extraction, upgraded electrics, and potentially a separate utility meter. It costs £18,000–£30,000, but it can also generate rental income or provide independent living space for a family member.

Not sure which room type suits your space?

Every garage is different, ceiling height, natural light, proximity to drains, and access all play a part in what works best. A local garage conversion specialist can visit your property, assess the space, and recommend the most practical option for your budget.

Do You Need Planning Permission for a Single Garage Conversion?

Most single garage conversions don't require planning permission, but there are important exceptions.

When You Don't Need It

Converting an attached garage usually falls under permitted development rights, provided the work is mainly internal, you're not changing the external appearance significantly, not extending beyond the existing footprint, and the property isn't a flat. Replacing the garage door with a brick wall and window is generally accepted.

When You Do Need It

You will need planning permission if: Your home is in a conservation area or is a listed building The garage was a condition of original planning approval You're converting a detached garage into a separate dwelling Your permitted development rights have been removed

Even without planning permission, you will need building regulations approval. This covers structural integrity, thermal insulation, fire safety, ventilation, damp-proofing, and electrical safety.

Cost-Saving Tips for a Single Garage Conversion

There's no need to compromise on your specification to reduce costs. A few well-considered decisions early in the project can save you thousands without affecting the quality of the finished room.

Keep your existing floor slab: If a structural engineer confirms it's sound and level, insulate on top with rigid foam boards instead of digging it up. That alone saves £1,500 - £2,500. Skip the plumbing: Every pipe run adds cost. If you don't strictly need a bathroom or kitchen in the space, keeping the conversion dry is the single biggest saver. Choose standard materials: Engineered wood flooring, off-the-shelf internal doors, and standard emulsion paint look great and cost a fraction of bespoke alternatives. Same goes for a standard window and brick infill over bi-fold doors. Get multiple quotes: Prices vary, even between tradespeople in the same postcode. Posting your job on MyBuilder lets you compare quotes side by side and find the right balance of price and quality.

Find Single Garage Conversion Specialists Near You on MyBuilder

Post your project for free on MyBuilder to receive quotes from local tradespeople who are available and interested in your job. You can read reviews from previous customers, browse photos of completed garage conversions, and compare options side by side, so you can choose the right person for your project and your budget.

All tradespeople on MyBuilder undergo checks at registration - such as ID documents, company details, certifications for regulated jobs and skill assessments - allowing you to hire with confidence.

FAQ: Common Questions About Single Garage Conversions

How Long Does a Single Garage Conversion Take?

A straightforward conversion, bedroom or home office with no plumbing, typically takes 2 - 4 weeks from start to finish. More complex projects involving a bathroom, kitchenette, or significant structural work can stretch to 4 - 8 weeks.

Does a Garage Conversion Add Value to Your Home?

In most cases, yes. A well-finished single garage conversion can add 10–15% to your property's value, particularly if it creates an additional bedroom. If you're looking for inspiration, you can browse photos of completed garage conversion projects on MyBuilder to see the standard of work you should be aiming for.

Can You Convert a Garage Without Removing the Garage Door?

You can, and some homeowners prefer this approach because it's reversible. Insulated roller doors or glazed screens can be fitted behind the existing door, giving you a sealed, insulated room while keeping the option to revert. It's a good option if you think you might need the garage back for parking in future.

How Much Does It Cost to Insulate a Garage for Conversion?

Insulating the walls, floor, and ceiling of a single garage typically costs £500 - £1,500 for materials, plus labour. Rigid PIR boards are the most popular choice, they offer excellent thermal performance at a slim thickness, which matters when you're working within a compact 15m² space and can't afford to lose floor area.

Is It Cheaper to Convert a Garage or Build an Extension?

A garage conversion is significantly cheaper. The average single garage conversion cost of £5,000 - £15,000 compares very favourably to a single-storey extension, which typically costs £25,000 - £50,000 for a similar floor area.

For a full comparison, see our house extension cost guide.