Thinking about turning your garage into a living space? It’s a great way to add value and get extra room without building an extension.
In London, a typical single garage conversion costs between £10,000 and £20,000. For a double garage conversion, you’re looking at £12,000 to £45,000, depending on size and how fancy you want to go.
The final price depends on things like your garage type, what you want to use the space for, and the quality of materials.
London conversions cost more than elsewhere in the UK. Labour and materials are just pricier here.
A simple conversion—just making a basic room—sits at the lower end of the range. If you want plumbing, heating, or high-end finishes, costs climb.
Knowing what affects the price helps you budget and avoid nasty surprises. Here’s a breakdown of costs, what drives them up or down, and what to expect as you go.
Key Takeaways
- Single garage conversions in London cost £10,000 to £20,000, while double garages cost £12,000 to £45,000
- Your total cost depends on garage type, intended use, structural work, materials, and labour rates
- Most garage conversions don’t need planning permission, but you do have to follow building regulations and might need approval for some changes
Garage Conversion Costs in London
Converting a garage in London usually costs between £13,000 and £45,000. Size and complexity matter, of course.
London rates are often £10,000 higher than other UK areas because everything’s just more expensive here.
Typical Garage Conversion Price Range
A standard 16m² integrated or attached garage conversion comes in between £10,000 and £20,000. Most people spend around £14,500 to £15,000 for this size.
The condition of your garage makes a big difference. If it’s in rough shape, you’ll pay more to fix it up.
Quality of materials also bumps the price. Want something fancy? Expect to pay.
Planning permission, insulation, plumbing, and electrical work add to your bill. If you’re thinking of a granny flat with all the bells and whistles, budget £15,000 to £45,000.
Basic conversions are cheaper than ones needing bathrooms or lots of electrical work.
Garage Conversion Cost per Square Metre
On average, garage conversion prices in London are about £950 per square metre for basic projects. That’s way less than a new extension, which can run £2,200 to £3,300 per square metre.
If you want high-end finishes or custom features, the rate goes up. Simple designs with standard materials stay cheaper.
Cost Comparison: Single vs Double Garage Conversion
An 18m² single garage conversion typically costs £13,000 to £18,000. For a 36m² double garage, expect £27,000 to £36,000.
Double garage conversions cost about twice as much, but the cost per square metre drops a bit for bigger spaces. You get better value converting more space at once.
Single garage conversions are good for a home office or bedroom. Double garage conversions work if you want open-plan living or multiple rooms.
Types of Garage Conversions
Different garage types need different approaches, and each affects the cost and structural considerations. The type you have sets the scope of work and the final price.
Single Garage Conversion
A single garage conversion turns a standard one-car garage into living space. Usually, these are 12-16 square metres and cost £10,000 to £20,000 in London.
Single garages are perfect for a home office, bedroom, or hobby room. Smaller size means you’ll spend less on flooring, insulation, and heating.
Most single garages already have basic wiring, but you’ll probably need to upgrade it for lighting, heating, and power outlets.
The main challenge? Fitting everything you need without making it feel cramped.
Double Garage Conversion
Double garage conversions give you about twice the space—usually 30-36 square metres. The cost? £12,000 to £30,000 in London, but some high-end jobs hit £45,000.
With more space, you’ve got more options. Think large living area, a master bedroom with en-suite, or even two separate rooms.
You’ll need more materials and labour. Flooring, insulation, walls—it all adds up.
Bigger space also means higher heating and cooling costs. And, yeah, it takes longer to finish.
Integral Garage Conversion
An integral garage sits inside your house’s main footprint, usually under a bedroom or on the ground floor. These conversions typically cost around £20,500 in London.
They’re often simpler than detached garages because they share walls with your home. You get easier access to existing electrics, heating, and plumbing.
One thing to watch: floor level. Integral garages often sit lower, so you might need to raise the floor.
Since utilities are already there, you can save £1,000 to £4,000 compared to detached garage conversions.
Partial Garage Conversion
A partial garage conversion just transforms part of your garage, leaving some storage or parking. This option usually starts from £5,000, depending on how much space you convert.
You’ll need a partition wall to separate the living area from the garage. It’s got to be insulated and finished properly.
This works well if you still need to park a car or store stuff but want a utility room or home office.
Fewer square metres means lower costs for materials and labour. Still, you’ll need proper insulation, heating, and damp-proofing for the converted bit.
Main Factors Affecting Garage Conversion Cost
A few key things decide how much you’ll pay for a garage conversion in London. Size and condition of your existing garage, what you want to use it for, material quality, and labour rates all play a part.
Size and Condition of Existing Garage
Garage size matters—a lot. A single garage (about 16m²) costs £6,000 to £20,000 to convert. Double garages run £12,000 to £50,000 because there’s just more floor area.
If your garage has damp, structural issues, or old wiring, budget extra for repairs. A well-kept garage is cheaper to convert.
Type matters, too. Integral garages (built into your home) cost around £400 to £700 per square metre. Attached garages cost £750 to £1,000 per square metre. Detached garages are pricier—£1,000 to £1,600 per square metre—since connecting utilities is more work.
Purpose and Intended Use of the New Space
What you plan to use the space for really affects the price. A basic bedroom or office is cheaper than a space needing plumbing or special fittings.
Adding a bathroom bumps your costs by £2,500 to £5,000. Kitchen conversions are the priciest, adding £10,000 to £20,000 for counters, appliances, and plumbing.
Living rooms, offices, and bedrooms usually stay in the £1,000 to £1,250 per square metre range. Gyms or entertainment rooms might cost more if you want special flooring or soundproofing.
Quality of Materials and Finishes
Material choices hit both your upfront costs and long-term value. Budget options save money now but might need replacing sooner.
Premium stuff costs more but tends to last. Flooring can be basic laminate, or you can splash out on engineered wood or luxury vinyl.
Doors, windows, lighting—there’s a big price range.
| Feature | Budget Option | Premium Option |
|---|---|---|
| Flooring | Laminate | Engineered wood |
| Windows | Standard uPVC | Timber or aluminium |
| Doors | Basic hollow core | Solid wood |
| Lighting | Standard fixtures | Designer fittings |
Location and Labour Costs
London’s labour costs are 15-30% higher than the UK average. You’ll pay more for skilled trades here.
Here’s what daily rates usually look like:
- Plumbers: £170 to £220
- Electricians: £150 to £265
- Joiners: £150 to £200
- Plasterers: £100 to £150
- Painters and decorators: £100 to £200
Where you live in London matters, too. Central boroughs charge more and often have stricter parking rules, which can bump up your costs.
Building regulations and planning requirements can add extra expense, especially if you need pros who know the local rules.
Planning, Permissions and Legal Requirements
Most garage conversions in London fall under permitted development rights, so you don’t need planning permission. But you almost always need building regulations approval to make sure your conversion is safe and up to code.
Permitted Development Rights in London
If you keep the work internal and don’t enlarge the building, you can convert your garage without planning permission. That’s most standard conversions.
If you’re in a listed building or conservation area, though, you lose permitted development rights. You’ll need planning approval, even for internal work.
Parking is another issue. Some boroughs might object if street parking is tight and you’re removing garage space. It’s a bigger deal in central London.
When Planning Permission is Needed
You’ll need planning permission if you’re turning your garage into a separate dwelling, no matter who lives there. This applies even if it’s all internal.
Changing the exterior—adding windows, changing the roofline—also means you must apply. Planning permission costs £500 to £1,500 and usually takes 8 to 12 weeks, sometimes longer in tricky areas.
Building Regulations Approval
Building regs approval is a must for almost every garage conversion. It makes sure your new space is structurally sound, safe, insulated, and ventilated.
Key areas covered include:
- Structural stability—walls and foundations must support the new use
- Fire safety—escape routes and fire-resistant materials are required
- Thermal insulation—your conversion has to meet energy standards
- Ventilation—air circulation needs to be adequate
- Drainage and damp proofing—keeps moisture out
Your local building control department checks these applications. Expect to pay £500 to £1,000 depending on your borough and how much work you’re doing.
Design, Features and Specialist Options
The design choices and features you pick for your garage conversion can really swing the final cost and how much you enjoy the space. Upgrading heating, adding a kitchen, or putting in special lighting can add thousands to your budget. Sometimes it’s worth it, sometimes not—depends what you’re after.
Popular Garage Conversion Ideas
Your garage can turn into almost any room you want. The most common picks are a home office, bedroom, gym, or a playroom for the kids.
Many London homeowners also create self-contained annexes for elderly relatives or for a bit of rental income. It’s a clever way to make use of extra space.
A basic bedroom conversion usually runs £10,000 to £15,000. If you’re dreaming of an en-suite bathroom, tack on another £3,000 to £8,000 depending on your fixtures.
Home offices stay in high demand and don’t need much plumbing, so costs stay a bit lower. You’ll want to budget for insulation, heating, electrical outlets, and decent internet.
A gym conversion is similar, though you might need reinforced flooring if you’re planning to haul in heavy equipment.
Kitchen Garage Conversion
Adding a kitchen is one of the pricier garage conversion options. A simple kitchenette—think sink, small cooker, minimal units—starts at about £3,000 to £5,000.
A full kitchen with quality appliances and worktops? That can easily jump to £8,000 to £15,000 or more.
You’ll need plumbing for water supply and drainage. If your garage is far from your main water lines, expect connection costs to climb.
Gas connections for cookers add £500 to £1,500 to your budget. It’s something people sometimes forget, but it matters.
Building regulations require proper ventilation in any kitchen. Usually, you’ll need an extractor fan, and if your garage is stuffy, maybe some extra structural work.
Heating and Insulation Options
Insulation is a must in London’s climate. Expect to spend £1,500 to £3,000 to insulate walls, ceilings, and floors to meet building regs.
Without decent insulation, heating costs can get out of hand. No one wants to freeze in their new office.
Underfloor heating is pretty popular for garage conversions. Electric systems cost £75 to £100 per square metre installed.
Water-based underfloor heating costs more upfront—about £100 to £150 per square metre—but it’s more efficient over time.
You can also extend your existing central heating into the new space. That usually costs £500 to £1,500, depending on how far you are from the boiler and how many radiators you need.
Lighting and Electrical Considerations
Proper electrical work keeps your garage conversion safe and usable. A full installation usually costs £800 to £2,000, covering sockets, lighting circuits, and upgrading the consumer unit if needed.
Plan for at least four to six double sockets. Home offices or kitchens will probably need more for all the gadgets and appliances.
LED downlights remain the top choice for lighting—good distribution, plus energy efficiency.
If your main consumer unit can’t handle the extra load, you’ll need to upgrade it. That adds £400 to £800, but it’s worth it for safety and peace of mind.
Hiring Garage Conversion Specialists and Companies
Picking the right professionals for your garage conversion really changes the outcome. Workmanship, building regulations, and project management all hinge on who you trust with the job.
Choosing a Garage Conversion Company
Go for companies with real experience in London garage projects. Check their credentials, insurance, and ask to see recent work.
Most good firms will happily provide references and show off similar projects. It’s a good sign if they’re proud of their work.
Always get detailed written quotes from at least three different companies. Look for a breakdown of labour, materials, and any extras like building control fees.
Don’t just pick the cheapest quote—see what’s actually included. Sometimes the “bargain” isn’t such a deal after all.
Check for memberships in trade bodies like the Federation of Master Builders or Checkatrade. It’s not everything, but it shows they care about standards.
Read online reviews, but don’t stress over a couple of bad ones if the majority are positive.
Ask for a clear timeline. Most single garage conversions take 2-4 weeks, though it depends on the job and the company’s schedule.
The Role of Garage Conversion Specialists
Garage conversion specialists know the ins and outs of turning garages into living spaces. They’re used to dealing with damp-proofing, insulation, and ventilation quirks.
These folks coordinate all the trades you’ll need—electricians, plumbers, plasterers, the works. That means you don’t have to juggle a bunch of different contractors.
A good specialist will walk you through building regulations. Most conversions fall under permitted development, but you still have to meet standards for insulation, drainage, and electrics.
They’ll also offer advice on heating, window placement, and flooring. Their experience helps spot problems before they get expensive.
DIY vs Professional Garage Conversion
DIY garage conversions usually cost £4,500 to £10,000—about half the price of hiring pros. But you’ll need serious skills across a bunch of trades, and a lot of time.
You’ll have to handle plastering, electrics, plumbing, carpentry, and more. Some tasks, like electrics and gas, legally require certified professionals.
Even if you do most of it yourself, you’ll still pay for those specialist jobs.
Professional advantages:
- You get guaranteed workmanship
- The job finishes faster (2-4 weeks instead of months)
- Building regulations are handled
- You’re covered by insurance if things go wrong
DIY considerations:
- You need advanced skills in several trades
- It’s very time-consuming—often takes months
- Mistakes can get expensive
- You’re still responsible for building regs
Honestly, most homeowners get better value with specialists. The time saved and peace of mind are usually worth it.
Additional Costs and Common Upgrades
Some upgrades and finishing touches can really bump up your budget. Foundation work, plumbing, and high-quality finishes often end up as the biggest extra costs in a London garage conversion.
Structural Alterations and Foundations
You might need to reinforce your garage foundations, especially with detached garages or if you’re adding heavy new features. Most garages have concrete slabs built for cars, not people.
Foundation work, if needed, usually costs £2,000 to £5,000.
Changing the garage door opening means installing a lintel and building a new wall section. That’s typically £1,500 to £3,000.
Adding windows or new doors? Expect £800 to £1,500 per opening, including structural support.
Building regs might require new damp-proof courses and floor insulation. These upgrades add £1,200 to £2,500 but bring your space up to standard.
Plumbing, Bathrooms and Utility Installation
If your garage doesn’t have plumbing, installing it costs £1,000 to £4,000 in London. A simple toilet and sink sits at the lower end, while a full bathroom with a shower or bath costs more.
Typical plumbing upgrade costs:
- Basic toilet and sink: £1,000-£1,500
- Full bathroom suite: £3,000-£6,000
- Kitchen plumbing: £1,500-£2,500
- Underfloor heating: £2,000-£4,000
Running pipes to a detached garage is pricier. You’ll probably need to dig trenches for drainage. Gas supply for heating adds £800 to £1,500.
Finishes, Fixtures and Furnishings
Your choice of finishes really affects the final cost. Laminate flooring is budget-friendly at £20-£30 per square metre, while engineered wood or quality tiles run £40-£80 per square metre.
Painting and decorating costs £300-£800 for a single garage.
Fixture and fitting price ranges:
- Internal doors: £150-£400 each (with fitting)
- Lighting fixtures: £200-£600 total
- Radiators: £150-£300 each
- Built-in storage: £500-£2,000
Kitchens for a granny annexe or studio flat start at £3,000 for basic units and appliances. Go for high-end fittings and you’re looking at £8,000 or more.
Custom storage solutions cost £150-£250 per metre in London. Bespoke features and premium finishes can easily add £5,000-£10,000.
Frequently Asked Questions
Converting a garage in London comes with a lot of cost considerations. Most people wonder about planning permission, how size affects price, and what can drive costs up.
What is the typical price range for converting a garage into a living space in London?
A simple single garage conversion in London usually costs between £5,000 and £10,000. More complex projects range from £12,000 to £30,000, depending on what you want.
Double garage conversions average around £45,000, since there’s more space and materials. You should budget £625 to £1,250 per square metre.
Basic conversions with minimal changes stick to the lower end. High-end jobs with luxury finishes can go over £40,000.
Can the cost of a garage conversion in London vary based on the size of the garage?
Absolutely, size makes a big difference to the total cost. Bigger garages need more materials, more labour, and more time.
A typical 16 square metre single garage costs about £15,000 to convert. Double garages, with all that extra space, average £45,000.
You actually pay more per square metre for smaller garages, since fixed costs (planning, design, utilities) don’t shrink with size. Attached garages cost £10,000 to £20,000, while detached ones run £15,000 to £25,000.
What are the key factors that influence the price of a garage conversion in London?
Your garage type is a big factor. Detached garages usually need more complex work, which means higher costs.
How you plan to use the space matters too. A storage room is cheaper than a full-on home office or bedroom with plumbing and electrics.
Structural changes—adding windows, doors, or partitions—add to your budget. Skilled labour and special materials don’t come cheap.
Material choices also impact the total. Quality flooring, custom cabinets, and premium fixtures cost more than basic options.
Labour is a huge part of your spend. You’ll need electricians, plumbers, joiners, plasterers—each charging £20 to £50 per hour in London.
How does obtaining planning permission affect the cost of garage conversions in London?
Most garage conversions in London don’t need planning permission. If you’re just changing the inside and not the external structure, you’re usually fine under Permitted Development.
You’ll need permission if you live in a conservation area, have a listed building, or plan major external changes.
Planning permission adds time and money—application fees and architectural drawings can bump up your upfront costs.
Are there any hidden costs I should be aware of when budgeting for a garage conversion in London?
Waterproofing and moisture control often catch people off guard, costing £1,000 to £3,000. Garages weren’t built to be lived in, so you need proper damp-proofing.
Insulation is key for keeping heating bills down. Set aside £750 to £1,000 for wall and roof insulation.
Building regs might require extra work you didn’t plan for. Inspections and certificates add to expenses, but they’re necessary for safety.
Utilities and plumbing costs depend on your current setup. Detached garages often need new electrics, water pipes, or gas lines—usually £1,000 to £4,000.
Sometimes, you’ll find hidden structural issues during the build. Older garages might need foundation repairs or wall reinforcement that wasn’t obvious at first.
How do different types of garage conversions, such as adding a bathroom or kitchen, impact the overall cost in London?
Converting your garage into a bedroom or living space usually costs less. Most garages already have basic electrical wiring, so you dodge the headache and expense of major plumbing work.
If you want to add a bathroom, brace yourself for a bigger bill. Plumbing requirements mean you’ll need water pipes, drainage, and probably a connection to your home’s main sewage line.
Turning a garage into a kitchen? That’s almost always the priciest route. Kitchens need plumbing for water and waste, gas lines for cooking, and extra electrical circuits for all those appliances.
A home office conversion sits somewhere in the middle. You’ll need decent insulation, heating, and enough electrical outlets, but you can skip the plumbing entirely.
Media rooms or home gyms aren’t too tough on plumbing, but they do need a fair bit of electrical work. Plan for extra circuits to handle entertainment systems or gym equipment.
Wine cellars are a different animal. You’ll need specialised climate control—temperature and humidity regulation gear can tack on another £2,000 to £5,000 to your overall costs.
