Garage Conversion Cost

Thinking about a garage conversion?

This home improvement can increase your living space and often add value to your property. By converting a garage into a new room, you can create a home office, bedroom, or family living space without extending your footprint.

This guide provides a clear breakdown of average garage conversion costs, including labour, materials, and the factors that make prices vary.

Even if you’re only exploring your options, it’s worth getting a few quotes. It helps you see what’s realistic for your budget and compare like-for-like offers from qualified specialists.

Getting quotes early also helps with planning. Many builders are booked up months in advance, so starting now gives you more flexibility and time to make the right decision.

It's quick and easy to get free, no-obligation quotes from garage conversion specialists near you using MyJobQuote.

Find our full garage conversion guide below!

How Much is a Garage Conversion?

The cost of a garage conversion can vary significantly, typical prices range from £10,000 to £32,000, with most projects averaging around £14,500.

This range reflects the huge variety in project sizes and specifications, from basic single-garage conversions with minimal structural work to double or detached garages that require more extensive construction.

Smaller single garages usually sit towards the lower end of the scale, often in the £10,000 to £20,000 range. Converting a double garage or a detached structure is usually more expensive, typically £20,000 or more, due to the larger floor area and the additional insulation and service connections required.

High-spec projects that include plumbing, an en-suite, or bespoke finishes can climb well above £30,000.

Estimate your Garage Conversion Cost

Want a clearer figure for your conversion? Try our free garage conversion cost calculator. It adjusts for garage type, location and any plumbing or electrical work required.

Garage Conversion Prices

The size and type of your garage are two of the biggest factors influencing cost. A single garage in the UK is usually around 18m², while a double garage averages 36m². Detached garages generally cost more to convert, as they often require extra insulation, plumbing and electrical work.

Below are the average garage conversion costs by size and type:

Integral garages are built into the main house and usually the most cost-effective to convert. They are usually insulated on two walls already, and typically have electrical connection.

Attached garages share a wall with the property and sit mid-range for costs.

Detached garages are self-contained structures, often the most expensive to convert because they may need extra foundations, insulation, and service connections.

If you are unsure which type of garage you have, see our garage types section below.

Key Things to Consider Before Your Garage Conversion

• Where will you park your car? Converting your garage means losing a dedicated off-street parking space. If you don't have a driveway, converting your garage may mean you have to park on the street. If your property's original planning permission required the garage to be kept for parking, you will likely need to re-apply for permission to get this restriction removed.
• How will it affect property value? While a well-done conversion often adds value to a home, in densely populated areas where on-street parking is at a premium, the loss of a garage can be a major drawback for potential buyers. It is a key consideration that could affect the property's appeal and resale value.
• What is the intended use? Your conversion's purpose has a major bearing on the final cost. A simple conversion to a living room or home-office is much cheaper than adding a kitchen or bathroom.
• Could your garage contain asbestos? Older garages, especially those built before 2000, may have asbestos roofing or insulation. If you suspect this, you must mention it when getting quotes. A licensed specialist will need to test and safely remove any asbestos before work can begin. This less of a worry if your garage was built within the last 25 years.
• What is the condition of the existing structure? A garage conversion relies on the existing structure, including the foundations, walls, and roof. It's crucial to have a professional assess the condition of these elements to ensure they are sound and won't cause issues later on.
• Could there be hidden problems? Until work has started, you won’t know for sure that the underlying structure is sound. It's sensible to set aside an extra 10% to 15% in a contingency fund in case a problem is uncovered, such as issues with the foundations or drainage.

Factors that Affect Garage Conversion Costs

Every garage conversion is unique. The final price depends on factors like the type of garage you have, the materials and finishes you choose, and whether you take on some of the work yourself or hire professionals.

Converting your garage into a kitchen or bathroom is also considerably more costly when compared to another living room or bedroom.

The cost always depends on:

• The complexity of the job.
• The size of the space.
• What type of room you will be converting it to.

Size and Type of Garage

Before you can estimate costs, it’s important to know what type of garage you have. Each type comes with different design challenges and impacts how easily it can be converted into living space.

There are three main types of garages:

• Integral garage
  Built directly into the main structure of the house, often under a bedroom or next to a hallway. These are the simplest to convert because the walls, roof, and utilities are already connected.
• Attached garage
  Shares at least one wall with the main house but isn’t fully built in. Often found at the side or rear of a property. Conversion may need extra insulation or structural work to connect smoothly with the main home.
• Detached garage
  A stand-alone building, separate from the main house. These require the most work to convert, as plumbing, heating, and electrics usually need to be installed from scratch, as well as additional work for insulation and foundations.

If you’re unsure what type you have, a good starting point is whether your garage shares walls and services with the main house (integral/attached) or stands completely alone (detached).

Materials and Finishes

The final cost of your garage conversion is heavily influenced by your choice of materials and the quality of the finish. Some of the major material costs to consider include:

• Insulation: Properly insulating your new space is essential for energy efficiency and comfort. This includes insulation for the walls, ceiling, and floor.
• Flooring: The cost of flooring varies widely depending on the material. Simple laminate or carpet will be more affordable, while underfloor heating or high-end tiles will significantly increase the price.
• Windows and Doors: Replacing the existing garage door with a new wall and windows is a major part of the project. The number and type of windows, along with any new doors, will impact your budget.
• Utilities: Adding plumbing for a bathroom or kitchen, or extending your home's existing electrical system for new lights and sockets, will add to the cost.

Garage Conversion Costs by Use

There are very few restrictions on the type of room you can convert your garage into, but your choice will have a significant bearing on the final cost. The most popular conversion types include:

• Bedroom or guest room - One of the cheapest options. Usually only requires insulation, electrics, flooring, and decoration.
• Living room or family room - Similar to a bedroom conversion, straightforward and budget-friendly.
• Home office - Low cost unless you add specialist wiring, built-in storage, or soundproofing.
• Home gym - Mid-range costs depending on flooring, ventilation, and whether you add reinforced structures or equipment.
• Home cinema or man cave - Also mid-range. More expensive if you install soundproofing, specialist lighting, or AV systems.
• Utility room - Higher cost due to plumbing, drainage, and ventilation requirements.
• Bathroom or shower room - High-cost option. New pipes and drainage can add £1,000–£3,000 to the project.
• Kitchen conversion - Among the most expensive. Requires plumbing, gas (optional), drainage, and fitted units.
• Annex or granny flat - The costliest type of conversion, as it combines a bedroom, bathroom, and kitchen into a self-contained space. Often needs planning permission.

As a general rule, the simpler the room, the cheaper the conversion will be. Specialist, plumbing, wiring, drainage, or soundproofing and ventilation, will push the project into a higher price bracket.

Cost of Converting a Garage into a Bedroom

Converting a garage into a bedroom is one of the most popular and cost effective conversions you can make.

The price varies depending on whether you are converting a single or double garage, and what additional features you want to include.

The cost to convert a single garage into a bedroom ranges from £10,000 to £20,000, with the average job taking around 2 to 4 weeks to complete. Converting a double garage will cost more, with an average range of £20,000 to £40,000, but this gives you a much larger space that could be used for larger wardrobes, or a bedroom with an en-suite.

Adding an en-suite bathroom will significantly increase the cost as this will require new plumbing and drainage.

Cost of Converting a Garage into a Kitchen

A kitchen extension price can depend entirely on the size of the room, the quality of materials used and the appliances.

For example...

• Small kitchen garage conversion - up to £10,000.
• Large kitchen garage conversion - up to £30,000.

What about kitchen worktops?

For a kitchen on a budget, typical materials for a worktop cost approximately £18 to £35 per m² to the more common higher-end granite surface that adds up to a higher price of £150 per m² and beyond.

However, the most expensive material available is Corian which typically costs £500 per m².

Take into account the low-level cost for kitchen appliances and the cost can escalate very quickly.

If your current kitchen is attached to your garage then you may be able to reduce costs by remodelling your kitchen around your extended space. You could add to your current kitchen using the same fixtures to main the room flow into the converted garage.

Cost of Converting a Garage into a Bathroom

When planning for a bathroom, you need to take into account the need for additional plumbing or whether you can connect to the existing supply without too much of an increase to the overall price.

As an indication on price, plumbing alone could add £1,000 to £3,000 to the bill as well as an additional 3 days.

If adding a simple toilet, the price for an average unit starts at £100 for a bathtub you could be looking at a 4-hour job with a standard bath costing £200.

Considering the average hourly rate of a plumber at approximately £45 to £50, that’s almost £350 just for setting up a bath.

But that's not all!

You may also want to consider installing an extractor fan, inclusive of the unit price, this would cost a further £150.

Cost of Converting a Garage into a Granny flat

Turning your garage into a self-contained annex or granny flat is a popular choice for families who want independent space for an elderly relative, or for homeowners looking to generate rental income.

This type of garage conversion is usually the most expensive because it requires creating a complete living space. It includes installing a new kitchen, bathroom, and bedroom, along with all the necessary plumbing, drainage, electrics, and heating.

Costs typically range from £25,000 to over £50,000, depending on the size of the garage and the quality of the finishes. Larger double garages or high-spec builds can climb even higher.

Because of the scale of the project, planning permission and building regulations approval is required, as you’re changing the use of the property to create a separate dwelling.

Partial or Half Garage Conversions

If you want extra living space but still need storage, a partial garage conversion can be a great compromise. This involves keeping part of the garage for storage, and converting the rest into a habitable room.

The amount of space available for converting into a liveable room will be reduced, but it may still be possible to convert between 7m²-13m² from a single garage. That's the equivalent of a single bedroom or double bedroom.

A common approach is to leave the garage door in place and build a stud wall a third of the way back. This keeps storage space at the front while creating a usable room at the rear.

A partial conversion:

• Retains valuable storage — a selling feature for many buyers.
• Keeps costs down, since blocking up the garage door and reinforcing foundations can be among the most expensive elements of a full conversion.
• Flexible use — popular choices include a utility room, small office, or playroom.

Costs for partial garage conversions typically range from £5,000 to £12,000, depending on how much of the space is converted and the finishes chosen. Projects that only require insulation, flooring, and stud walls sit at the lower end, while those adding plumbing, heating, or high-end finishes will cost more.

If you keep your garage door in place, remember to insulate it properly or consider replacing it — see our garage door replacement cost guide for details.

Additional Garage Conversion Costs

In addition to labour costs, there are other costs to consider, including:

Garage Flooring

Most modern garages will have ample flooring to begin work, but for those needing a little more attention, you may need to have concrete poured to level out any imperfections.

Some garages will also need their floor raised, as they need to be above the damp course in order to meet regulations.

Usually there are two options for this:

• Floating floor — A floating floor is typically the cheapest and quickest option.
• Concrete floor — The average cost of concrete would be £75 to £95 per cubic metre, with the most common single garage being approximately 18m², a double garage is twice the size at 36m².

Garage Door

Replacing a garage door with additional windows costs within the region of £1,300 to £1,500.

An additional door for access can cost on average at about £750, the same average cost per stud wall to insulate the garage further.

Garage Heating and Water

You will need adequate heating for the colder months so the installation of a new standard boiler will cost within the region of £2,400 depending on the brand, i.e. Worcester, and your location; London and South East areas are known to be a premium price.

An alternative form of heating could be underfloor heating. The average cost of underfloor heating, which includes installation, would be £800 for the average-sized garage.

Garage Electricals

The average cost of adding additional electricity will be around the £600 to £700 mark, which includes labour and materials.

An extractor fan may also be needed for kitchen or bathrooms, expect to pay around £150 for the cost of a fan and the installation cost by an electrician.

What’s Included in a Garage Conversion?

Although each garage conversion is unique, most follow a similar process, but not every quote covers the same items. Here’s what is typically included when turning your garage into a habitable room:

• Structural changes: Removing or blocking up the garage door, adding stud walls, and fitting new windows or doors.
• Insulation: Bringing walls, floor and ceiling up to building regulation standards.
• Flooring: Levelling or raising the floor above the damp course; some projects use a floating floor while others pour new concrete.
• Electrics: Wiring for lights, sockets, and any heating or appliances.
• Plumbing (if required): Kitchens, bathrooms, or utility rooms will need new pipes, drainage, and ventilation.
• Heating: Extending central heating, adding radiators, or installing underfloor heating.
• Plastering and finishes: Internal walls and ceilings plastered, decorated, and fitted with skirting boards and flooring.
• Trades and paperwork: Quotes may include specialist trades such as structural engineers, as well as building regulations approval.
• Waste removal: Disposal of old doors, rubble, and construction debris.

When comparing quotes, check carefully whether items such as plumbing, electrics, heating, and finishing work are included.

Most contractors will give a quote for the overall job, though some specialists will include all the jobs in the price, including structural engineers and the relevant paperwork. Always ask for a detailed breakdown so you can compare like-for-like.

Supply Only Costs

Considering a DIY job?

If so, you need to consider the supply costs for various garage conversion, which you can find below:

Kitchen Conversions

Bathroom Conversions

Additional Materials

Labour Costs and Time Scales

If you plan on hiring professionals to convert your garage, you should consider the costs of various trades which are set out in the table below.

Expect the time to increase, as well as the costs, should the work be for a double garage or around London areas.

Another main factor to consider is how far away the garage is from the property.

Integral garages are the most cost-effective, but the further it is away from your home, the more it costs for things such as connecting electricity and pipework for kitchen or bathroom conversions.

Planning Permission for a Garage Conversion

Generally speaking, planning permission isn't required for a garage conversion - especially if the garage is integral or connected to the house.

This is often considered as Permitted Development and gives homeowners the power to make home improvements without any further applications for permission.

Additional conditions also may apply, and while you don't need the planning permission as such, you may need to have these conditions removed before continuing.

Changing the outward appearance of the garage such as removing or bricking up the door, and installing front facing windows, may also require further permission.

Building Regulations Approval

Even if planning permission is not required, building regulations approval is always needed for a garage conversion. This ensures the new room is safe, energy-efficient, and legally habitable.

Building regs cover the following:

• Structural stability and foundations.
• Insulation, damp proofing, and ventilation.
• Electrics and plumbing.
• Fire safety and escape routes.

Any time you change the purpose of a building, you need it to be authorised first.

With smaller developments, you can apply for a building notice application, which has an estimated cost of £200-£500.

For more significant works, a full Buildings Regulations application may be required which will mean you have to submit plans in advance. Expect the price to increase if you are extending more than one dwelling or if building in a conservation area. Prices are dependent on your local Building Control, and approval can take between 5-8 weeks.

Other Permissions

Additional permissions may be needed depending on where you live (e.g., if you're in a conservation area). In cases like these, you would need to apply for planning permission; therefore, it is recommended to check first with your local authority before continuing.

If you share a wall with one or more neighbours, you may have to adhere to the Party Wall Act. Unless you can get a waiver from them, expect to pay within the region of £700 to £1,000 per neighbour to complete a Party Wall Agreement form.

To get more insight into the construction sector, be sure to check out our Construction Industry Statistics guide (updated daily).

What's Involved in Converting a Garage?

Preparation

With all conversions comes the planning, preparation and design work of the build. You can hire an architect or structural engineer to help you with the following:

• Inspecting the garage to confirm whether any structural repairs or reinforcements are necessary
• Completing and submitting paperwork with Building Control and confirming if planning permission is relevant (most likely if the property is detached or in a conservation area)
• Checking for shared walls with one or more neighbours and waivering the Party Wall Agreement

The Build

When it comes to day one of the build, your contractor will:

• Strip down the garage and remove everything surplus
• Determine if the floor will be levelled, raised and poured with new concrete, though if built within the last 25 years and good condition, this step may not be needed
• Remove the garage door
• Install any new access doors or windows and lay the appropriate brickwork to support the new installations.
• Damp proof and insulate the building
• Install any stud walls, costing £850 each on average and sectioning off the space if the area is to be split into multiple rooms
• If applicable, re-wiring and circuit boards are installed as well as plumbing, or if the existing house supply can support it, cables and pipes can be connected to the existing installations
• Flooring is installed – under flooring if required at this point.
• Plastering of the walls
• Painting and decorating, plus making good where needed

Can I Convert a Garage Myself?

It is feasible to be able to convert a garage yourself. The obvious question would be whether you have the expertise to carry out the work, but also whether you are familiar with the steps you need to take from the design stages through to having the work signed off where appropriate.

There is a high risk in terms of health and safety, as well.

• There is the physical aspect of the work - if you are doing it alone, the heavy lifting involved could have an impact on your health.
• If installing new facilities, a mistake with existing wires or plumbing could be catastrophic - worse still, fatal.
• Getting the measurements and using the right sort of materials may not become apparent until completion. Everything may appear good on the surface, but if you haven't applied the correct planning of the build, it could end up being costly in the future.
• Does the conversion have suitable acoustics, ventilation, energy efficiency and fire safety precautions?

Looking for a budget option?

A DIY conversion could save a significant amount of money due to labour costs.

You would need to consider whether you have the time to be able to do yourself as it will take much longer and you might not necessarily be able to pick up the materials for the same trade prices as the professionals.

While you have complete control over the conversion, the added time and potential costs of materials may eventually eat into the budget.

The benefits of having tradespeople completing the work include:

• Professional finish
• Guaranteed/insured to a high standard
• Knowledge and expertise
• Foresight whether additional works needs to be completed to save having it done in the future at a higher cost
• Saves your time and energy

Sometimes it is worth hiring professionals to save time and for peace of mind. An architect, for example, can save a lot of hassle by completing and submitting the paperwork required by Building Control on your behalf.

Additionally, hired professionals are insured for the work they carry out - any discrepancies can be addressed accordingly.

Will I Need an Architect?

An architect can include aspects of the design that you may not have accounted for from aesthetics to safety.

As a professional, they are not only experts in the design of your new conversion, but up-to-speed with the paperwork and potential implications if not completed correctly.

With the architect's services, they are able to deal with your local Building Control and adhere to Building Regulations where applicable - an area that could easily be overlooked if you were to complete the work yourself.

Architect fees are usually within the £500 to £2,000 range.

Will I Need a Structural Engineer?

As well as the architect, you may need the services of a structural engineer to sign off work.

Structural engineer costs start at around £250 for the initial visit, with their typical hourly rate in the region of £60 to £110.

They may be able to provide advice on any additional foundation work required before work commences. For instance, whether the structure will still be sound if you're removing a garage door and replacing it with a window.

You can, of course, complete the planning work yourself, but at the very least would need a structural engineer to inspect the building at the very minimum.

Flooring for Converted Garage

Depending on your existing floors, you may need to have new concrete poured before you can make a start on carpets, tiles or wooden floors.

Most modern garages should be ready to go, but for older properties, a new concrete floor may be required. Concrete prices are based on the area of coverage–the average cubic metre costs within £65 to £85.

The options for flooring are mostly selected based on preference and budget.

Vinyl Flooring

Looking for a cheap option?

Vinyl flooring could be viable and a good bet for kitchen or bathroom conversions.

Available in vinyl sheets that offer complete coverage or available as luxury tiles that can be replaced individually as and when required. The common price for vinyl sheets is around £18 per m².

Wooden Flooring

Available both as laminate flooring and natural wood, wooden flooring offers a natural, authentic look. Average prices are within £30 per m².

Tile Flooring

Tiled flooring is a good robust option, however you'll need a very level floor for this to be an option which sometimes isn't possible when joining a garage conversion with another room.

Tile flooring can be an excellent choice for any room, and they have a sophisticated, sparkling finish. There are many different alternatives to choose from, but most tile flooring costs per square metre are around £20.

Choosing Garage Lighting

The cost of lighting up your new garage conversion will depend upon the room and the mood you would like to create in it. Conventional bathroom and kitchen lights are best suited with downlights that are integrated into the ceiling, maximising space. Alternatively, wall lights or even spotlights can either offer subtle up lighting or focal points in a room.

Downlights

Downlights are best suited where space is limited, or you require more areas to be lit, but that is cost-effective.

A typical unit costs approximately £8 and usually are LED-based meaning that they last quite long and easy to replace.

Spotlights

Spotlights are suitable for lighting any type of room. While there are dimmable options, they tend to be more suited for darker rooms or those needing focal points of light. The average cost for a unit is £40 to £65.

Wall Lights

On average, wall lights cost around the £22 mark, but as they are easily accessible and don’t require any additional structural support, designs can be quite extravagant with high street prices exceeding £100 per unit.

Where Can I Dispose of the Garage Door?

A lot of companies will recycle your garage door, and this is included in the price of installation, and not a separate job as it is usually completed at the time of the conversion.

However, for those environmentally aware, local councils will collect this type of material usually for a small fee as indicated by the local authority. This is a quick option and pending you notify them in advance and pay the fee; they will take it away for you.

Some councils offer this service for free, but some London areas can charge £25 for 1 to 3 items.

Alternatively, you may be able to sell the door on a local classified site such as Gumtree or eBay.

Bear in mind that these would need to be advertised as collection only due to the size and weight. Sale prices greatly vary as a simple metal door can go for £130 whereas an electric double-sized door can sell for as much as £1,150.

Hiring a Garage Conversion Specialist Checklist

With the number of experts required for the average garage conversion, it can be overwhelming on what to look out for when hiring a professional.

The following is a checklist that applies to each contractor needed to complete your garage conversion:

• First of all, get plenty of quotes – 2 or 3 as the bare minimum and get them in writing. There isn’t a fixed price, regardless of the room you wish to set up, as there are so many elements to consider.
• On that basis, have the contractor visit your property to ensure there are no added costs from the outset, and if there is likely to be any additional charges, what are they likely to be?
• Ask to see examples of previous work, review testimonials and check to see whether the tradesperson belongs to any guilds.
• Confirmation of any guarantees of craftmanship, indemnity insurance and all that applies in this area.
• Confirm a payment plan or when work will be paid in full. Do not pay all fees upfront.
• When work starts, ensure that the contractors have full access to the work area as any delays may be charged at full daily rates.
• Some companies will include all the design work and will apply for planning permission on your behalf, but it is your responsibility that this is honoured, so make sure this is carried out before work begins.
• Ensure you are happy with the work carried out.

FAQs

Sources

https://www.planningportal.co.uk/
https://www.gov.uk/building-regulations-approval/how-to-apply
https://www.propertypriceadvice.co.uk/home-improvements/garage-conversions-questions-answered