Garage Conversion Cost in 2026: What Converting a Garage Really Costs
The short answer
- £9,000 to £19,500 for most single garage conversions, the middle of five UK cost guides
- £8,000 to £14,000 for an integral garage, £18,000 to £30,500 detached and £20,000 to £30,500 for a double
- No planning application for most in England if the work is internal, but building regulations approval is needed
- About £80 a year to heat a converted 15 m² single garage on gas, on our heat model
Retrofit Planner's comparison of five UK cost guides puts most single garage conversions at £9,000 to £19,500 in 2026. An integral garage, built into the house under the main roof, is the cheapest at £8,000 to £14,000; a detached garage costs £18,000 to £30,500 and a double garage £20,000 to £30,500. There is no official price data for garage conversions, so every range here is the middle half of the published prices, which we show side by side below. Most conversions in England need no planning application, but all need building regulations approval, which brings in insulation, a damp proof floor and a safe way out in a fire. On our heat model, heating a converted single garage of about 15 m² adds about £80 a year to a gas bill.
Garage conversion cost by garage type
Converting a single integral garage costs about £8,000 to £14,000, an attached garage £10,000 to £20,000 and a detached garage £18,000 to £30,500. A double garage costs about £20,000 to £30,500.
| Garage | Typical cost | Time on site |
|---|---|---|
| Single, integral | £8,000 to £14,000 | 2 to 6 weeks |
| Single, attached | £10,000 to £20,000 | 2 to 6 weeks |
| Single, detached | £18,000 to £30,500 | 6 to 10 weeks |
| Double, any type | £20,000 to £30,500 | 4 to 10 weeks |
The data behind this table
The middle half of the prices for each garage type published by MyJobQuote, BestBuilders, Trade2Base and Rated People, read on 11 November 2026, worked out the same way as our other ranges (see "How we work out our range" below). Only three of the guides price an attached garage, so treat that row as rougher. The guides put a single garage at 12 to 18 m² and a double at 25 to 36 m². Times are the spread of what MyJobQuote, BestBuilders and Rated People say.
Read the detail
An integral garage is already inside the walls and under the roof of the house, so the job is mostly the front wall, the floor, insulation and finishes, and the heating and electrics only have to come a few metres. An attached garage often has a roof of its own to insulate, and Rated People adds £450 to £940 for ceiling joists on attached and detached garages. A detached garage costs most because the services have to cross the garden: Trade2Base mentions a new electrical sub-main and a drainage run, and MyJobQuote puts water, drainage and electricity connections at £1,000 to £4,000.
What the room becomes matters as much as the garage. On MyJobQuote's figures, a basic living room or office in a single garage costs £8,000 to £12,000, a bedroom with an en suite £15,000 to £22,000 and a kitchen £20,000 to £25,000, before a mid-range or premium finish. BestBuilders gives a real example: a 16 m² integral garage in Leeds, turned into a bedroom in March 2026, cost £16,400 including VAT and took 4 weeks on site.
Region matters too. MyJobQuote puts London and the South East 15 to 25% above the national average and northern England, Wales and Scotland 10 to 20% below it; BestBuilders puts London and the South East 25 to 35% higher, and Rated People says labour there can cost up to 20% more.
What five cost guides say
Published prices for converting a single garage run from £8,000 to £29,040. Our range is the middle half of every figure the five guides give, which sets aside the cheapest and the dearest.
| Guide | Single garage | Single, detached | Double garage |
|---|---|---|---|
| MyJobQuote, updated 5 November 2026 | £8,000 to £14,000 integral; £10,000 to £20,000 attached | £20,000 to £31,000 | £20,500 to £45,000 |
| BestBuilders, updated 1 September 2026 | £8,000 to £12,000 integral; £10,000 to £18,000 attached | £18,000 to £35,000 | £15,000 to £30,000 for 25 to 35 m² |
| Trade2Base, 8 June 2026 | £8,000 to £14,000 integral, basic room, VAT extra | £10,000 to £18,000, plus new services | £15,000 to £25,000 open plan; £20,000 to £35,000 for two rooms and an en suite |
| Rated People, 2026 prices | £19,800 integral; £29,040 attached (averages, 18 m², VAT included) | £30,140 | £20,460 integral, £30,085 attached, £31,130 detached (36 m²) |
| HomeOwners Alliance, undated | £8,500 to £20,000 for 15 m², type not given; average £14,250 | Not given | Not given |
| Our range: the middle half | £9,000 to £19,500 | £18,000 to £30,500 | £20,000 to £30,500 |
The data behind this table
Read on 11 November 2026. Trade2Base leaves VAT out, Rated People includes it in its table, and BestBuilders says its summary ranges include it; MyJobQuote and the HomeOwners Alliance do not say. BestBuilders' figures come from its own regional cost model, and Rated People's from PriceBuilder with tradespeople from more than 30 trades. MyJobQuote, Trade2Base and the HomeOwners Alliance do not publish a sample or method. Checkatrade's and MyBuilder's garage conversion pages refused our requests, so their figures are not in the table.
Read the detail
Four of these guides come from websites that match homeowners with tradespeople (MyJobQuote, BestBuilders, Trade2Base and Rated People), and one from a homeowners' advice body (the HomeOwners Alliance). Rated People's averages are the highest; they include VAT and price every trade, from preliminary work to decorating. Trade2Base writes for builders pricing a job and leaves VAT out, so its figures are among the lowest.
Two guides also give a price per square metre: MyJobQuote £450 to £1,700, with most homeowners budgeting about £1,000, and BestBuilders £900 to £1,800. That is well below the cost of building new: our house extension cost guide puts a single storey extension at £1,700 to £2,400 per m², because a conversion reuses walls, a roof and foundations that are already there.
How we work out our range
For each column we put every published figure into one list: both ends of a range, or the single average where that is all a guide gives. The single garage column takes each guide's integral and attached figures and the HomeOwners Alliance range; detached garages have their own column. Our range is the middle half of that list, from its lower quartile to its upper quartile, rounded to the nearest £500. For a single garage the list is £8,000, £8,000, £8,000, £8,500, £10,000, £10,000, £12,000, £14,000, £14,000, £18,000, £19,800, £20,000, £20,000 and £29,040, which gives £9,000 to £19,500. A single unusually high or low guide moves the range very little.
Where the money goes
In a single integral conversion, the wall that replaces the garage door and the insulation and plasterboard take about half the budget. Electrics, heating, the floor and fees make up the rest.
| Part of the job | Trade2Base, 15 to 20 m², VAT extra | BestBuilders, typical £12,000 job |
|---|---|---|
| Removing the door, new wall and window | £500 to £1,500 | About £2,900 (24%) |
| Insulation and plasterboard | £600 to £1,200 insulation, £600 to £1,000 plastering | About £3,100 (26%) |
| Electrics | £800 to £1,500 | About £1,550 (13%) |
| Heating | £500 to £1,200 | About £1,100 (9%) |
| Floor | £400 to £900 for the screed | About £1,200 (10%) |
| Decorating and fees | £300 to £700 decorating, plus £300 to £700 building control | About £2,150 (18%) |
Read the detail
Most quotes leave some items out. These are the extras the guides price separately:
- Building control: £300 to £1,200 on MyJobQuote's figures, £400 to £900 on BestBuilders' and £300 to £700 on Trade2Base's.
- Drawings: £500 to £2,500 (MyJobQuote) or £400 to £1,200 (BestBuilders); Rated People says drawings for a planning application start at about £2,000.
- Structural engineer: £500 to £1,200 if a load-bearing wall is affected (MyJobQuote).
- Damp proofing and insulation upgrades: £1,500 to £5,000 (MyJobQuote) or £1,500 to £4,000 (BestBuilders), more where the garage floor or walls need a lot of work.
- An en suite: £3,000 to £7,000 for a shower room (BestBuilders), or £5,500 to £9,000 for a bathroom (MyJobQuote).
- A planning application, if you need one: £548 in England (see the planning section).
- Contingency: MyJobQuote and BestBuilders both advise 10 to 15% on top.
Planning permission and permitted development
Most garage conversions in England need no planning application, as long as the work is internal and does not enlarge the building. Check first whether your home's permitted development rights have been removed, which is more likely on a newer estate.
| Your home | Planning permission? |
|---|---|
| A house, work inside the garage, nothing enlarged | Not usually needed |
| Permitted development rights removed, for example on a new estate | Needed |
| Conservation area, Article 4 direction or a planning condition | May be needed |
| A listed building | Listed building consent may be needed |
| A flat or maisonette | Permitted development does not apply |
| The garage becomes a separate home | May be needed, whatever the work |
Where these rules come from
The Planning Portal's guidance on garage conversion planning permission, which covers England. It says permission "is not usually required, providing the work is internal and does not involve enlarging the building", that permitted development rights for garage conversions have sometimes been removed, "particularly if you live on a new housing development or in a conservation area", and that its allowances apply to houses, not flats and maisonettes.
Read the detail
Permitted development rights are often taken away by a condition on the original planning permission for an estate, for example to keep the garage for parking. Look at your title deeds and the council's planning records before paying for drawings; the HomeOwners Alliance suggests the same. If the rights are gone, you need a planning application. Government planning fees rise each 1 April, and since 1 April 2026 a householder application in England costs £548 (GOV.UK fee indexation). BestBuilders says a decision can take up to 8 weeks.
If you do not need permission, a lawful development certificate proves the work was lawful, which helps when you sell. It costs half the planning application fee, £274. These rules are for England. Wales may differ, and Scotland and Northern Ireland have their own systems.
Building regulations: damp, fire escape and ventilation
Turning a garage into a room you live in normally needs building regulations approval, even when it needs no planning permission. Building control checks the new wall's foundation, a damp proof floor, insulation, ventilation and a safe way out in a fire.
| Item | What is usually needed |
|---|---|
| The wall where the door was | A new foundation may be needed, because a garage's foundation is often not of the traditional kind |
| Floor and damp | A new damp proof membrane with insulation on top and a screed about 75mm thick, or a timber floor kept 150mm clear of the concrete with a damp proof course under the timber |
| Insulation | Walls, floor and roof brought up to Approved Document L (see the next section) |
| Escape from fire | The room opens onto a hall that leads to an exit, or has an escape window or door |
| Smoke alarms | Mains smoke alarms with a battery backup where the new room has no exit of its own |
| Ventilation | Trickle vents of 8,000 mm², or 10,000 mm² in a single storey home, and a window that opens to at least a twentieth of the floor area; an extractor fan in a new kitchen or bathroom |
Where these rules come from
The Planning Portal's building regulations pages for garage conversions: when approval is needed, the in-fill garage door, flooring and ventilation (the twentieth applies to a window that opens more than 30 degrees; one that opens 15 to 30 degrees needs a tenth). Escape and alarms from Approved Document B, Volume 1: Dwellings, 2019 edition incorporating the 2020, 2022 and 2025 amendments: paragraph 2.1 for rooms on the ground storey, 2.10 for escape windows, 2.11 for inner rooms, 1.8 and 1.2 to 1.4 for alarms, and 5.6 and 5.7 for a garage that stays next to the house.
Read the detail
Fire escape decides more layouts than any other rule. Under paragraph 2.1 of Approved Document B, every habitable room on the ground floor, other than a kitchen, needs either a door onto a hall leading to an exit or an emergency escape window or door. A converted garage reached only through another room, such as through the kitchen or a utility room, is an inner room, and paragraph 2.11 allows it only with an escape window. An escape window needs an opening part at least 450mm high and 450mm wide, with an area of at least 0.33 m², and its bottom no more than 1100mm above the floor. Paragraph 1.8 asks for a fire detection and alarm system where a new habitable room on the ground floor has no exit of its own, and paragraph 1.2 asks for smoke alarms to be mains operated.
If you convert only the front of the garage and keep a store behind, the part that stays a garage has to be separated from the house by fire resisting construction, at least REI 30 under paragraph 5.6, and any door between them should be a self-closing fire door with a minimum rating of E 30 S.
The floor is often the hardest part. A garage floor is often lower than the house floor, and the Planning Portal notes it may be worth raising it to match. Building control is done by your council or a private approver. Apply before the work starts, by full plans or a building notice, and keep the completion certificate: it is the proof that the room was signed off as habitable space.
Insulating and heating the new room
A converted single garage of about 15 m² adds about £80 a year to the gas bill, on our heat model. The walls, floor and roof must first be insulated to current Building Regulations standards, which keeps the cost down.
| Heating | Single garage, about 15 m² | Double garage, about 30 m² |
|---|---|---|
| Gas boiler | £80 | £160 |
| Heat pump, heat pump tariff | £60 | £125 |
| Oil boiler | £120 | £240 |
| LPG boiler | £100 | £205 |
| Electric heaters | £240 | £480 |
How we work this out
Our heat model puts a typical 3-bed semi at 11,000 kWh of gas a year at EPC band D. At the model's 90% boiler efficiency that is 9,900 kWh of heat over the 101 m² of floor the model implies for three bedrooms, about 98 kWh a square metre. A room built to today's insulation standards should use far less, so we scale that by 0.62, the ratio our model measures in the government's energy data for homes rated EPC band A or B against band D: about 61 kWh a square metre. For 15 m² that is about 910 kWh of heat a year, and for 30 m² about 1,820 kWh, the same as the loft room in our loft conversion cost guide. We price it at the Ofgem cap for October to December 2026 (gas 7.97p, electricity 26.32p), oil at 11.3p and LPG at 9.5p per kWh at 85% boiler efficiency, and a heat pump at an efficiency of 2.78 on an 18.7p heat pump tariff, rounded to the nearest £5. Like the model's figures, it includes a share of hot water, which a study or playroom may not add. Standing charges are left out because they do not change. A garage has more outside wall and floor for its size than a room inside the house, so treat the figure as a guide, not a measurement.
Read the detail
A garage that becomes part of the heated house counts as a "change to energy status" under paragraph 11.6 of Approved Document L, which names garage conversions as an example. Walls, floors and roofs that are kept should be upgraded where they are worse than the threshold in Table 4.3, and anything built new should meet Table 4.2:
| Part of the conversion | Maximum U-value | Rule |
|---|---|---|
| Existing wall, worse than 0.70 | 0.55 with cavity insulation, 0.30 with internal or external insulation | Upgrade, Table 4.3 |
| Existing floor, worse than 0.70 | 0.25 | Upgrade, Table 4.3 |
| Existing roof, worse than 0.35 | 0.16 | Upgrade, Table 4.3 |
| New wall where the door was, or a new floor | 0.18 | New element, Table 4.2 |
| New windows and doors | 1.4 | New fitting, Table 4.2 |
A U-value measures how much heat passes through a square metre of wall, floor or roof; lower is better. A garage wall of a single layer of brick or block with no insulation is usually far worse than the threshold, so the guides price insulation on the inside: BestBuilders' Leeds example used a stud wall with PIR insulation boards and plasterboard, and the HomeOwners Alliance suggests insulated plasterboard on timber battens. The rules allow some give: if insulating a wall to the full standard would take more than 5% off the room's floor area, or a floor would clash with the levels next to it, a lesser standard may be acceptable, and under paragraph 4.13 an upgrade that would not pay back within 15 years can stop at the best standard that does, generally no worse than 0.7. These figures are from the 2021 edition, incorporating 2023 amendments, which applies in England today; a new edition takes effect on 24 March 2027.
For heat, extending the central heating to the new room costs £500 to £1,200 on Trade2Base's figures, and MyJobQuote puts underfloor heating at about £800. Any heating that is extended should meet the standards for fixed building services in Approved Document L. Electric heaters are the cheapest to fit and the dearest to run, about three times the cost of gas. If your home has a heat pump, check that the new radiator is big enough for its lower flow temperature with our radiator size calculator.
How long a garage conversion takes
Usually 2 to 6 weeks on site for a single garage, and 4 to 10 weeks for a double or detached garage. Drawings, building regulations approval and any planning decision come first.
| Guide | Single garage | Double, detached or complex |
|---|---|---|
| MyJobQuote | 2 to 4 weeks, about 4 on average | 4 to 8 weeks |
| BestBuilders | 3 to 6 weeks | 6 to 10 weeks with new services |
| Rated People | 3 to 6 weeks, or 2 to 4 for a bedroom | 6 to 8 weeks with heavy structural or plumbing work |
Read the detail
A conversion with a bathroom or kitchen takes longer because of the drainage. On a detached garage, the trench for new services across the garden adds days before the inside work starts.
How to get quotes
Get at least three itemised quotes for the same job, and compare what each includes. A cheap quote that leaves out drawings, building control and the floor is not cheap.
Read the detail
- Ask for each line priced separately: drawings and building control, the new wall and its foundation, windows and doors, the floor, wall and ceiling insulation, electrics, heating, decorating and VAT.
- Ask how the floor will meet the level of the house, and how damp will be kept out of the floor and the new wall.
- Ask how the room will meet the fire escape rules: a door onto a hall, or an escape window.
- Ask whether your boiler or heat pump can take another radiator.
- Ask who applies for building regulations approval, and make sure you get the completion certificate.
We do not recommend builders yet, and no link on this page is paid. When we do, every firm will have to meet our trusted supplier standard. If you need more space than the garage gives, compare the cost of going up in our loft conversion cost guide, which puts a typical 30 m² conversion at £22,500 to £75,000, or building out in our house extension cost guide.
Frequently asked questions
How much does a garage conversion cost in the UK?
Most single garage conversions cost £9,000 to £19,500 in 2026, the middle half of the prices five UK cost guides publish. An integral garage is the cheapest at £8,000 to £14,000, an attached garage costs £10,000 to £20,000 and a detached garage £18,000 to £30,500. Fees and a contingency of 10 to 15% are usually extra.
How much does it cost to convert a double garage?
About £20,000 to £30,500, on the guides that price a double garage of 25 to 36 m². Two rooms, an en suite or a kitchen push the price higher: MyJobQuote's range for a double garage runs to £45,000.
Do I need planning permission to convert my garage?
Usually not in England, if the work is internal and does not enlarge the building, according to the Planning Portal. You may need permission if your home's permitted development rights have been removed, which is more likely on a newer estate, if it is in a conservation area or is listed, if it is a flat or maisonette, or if the garage will become a separate home. A householder planning application costs £548 in England.
Does a garage conversion need building regulations approval?
Yes. Turning a garage into a room you live in normally needs building regulations approval. Building control checks the foundation of the new wall, a damp proof floor, insulation, ventilation and a safe way out in a fire: the room must open onto a hall leading to an exit, or have an escape window or door. Building control fees in the guides run from £300 to £1,200.
How long does a garage conversion take?
Usually 2 to 6 weeks on site for a single garage and 4 to 10 weeks for a double or detached garage, according to MyJobQuote, BestBuilders and Rated People. Drawings, building regulations approval and any planning decision come first.
How much does it cost to heat a converted garage?
About £80 a year on gas for a single garage of about 15 m², on our heat model at the October to December 2026 price cap, or £160 for a double garage of about 30 m². Electric heaters cost about three times as much to run: £240 a year for the single garage.
Data sources
Updated 11 November 2026.
Prices come from five UK cost guides, read on 11 November 2026. Planning and building rules come from the Planning Portal, gov.uk and the Approved Documents, and heating costs from our own heat model.
Show every source
Garage conversion prices: MyJobQuote, How much does a garage conversion cost in the UK? (updated 5 November 2026); BestBuilders, Garage conversion cost UK (updated 1 September 2026, from its own regional cost model); Trade2Base, Garage conversion costs UK (8 June 2026, VAT excluded); Rated People, How much does a garage conversion cost in 2026? (first published 6 September 2022, prices stated as accurate for 2026, built with PriceBuilder); HomeOwners Alliance, Garage conversion: where do I start? (undated). All read on 11 November 2026.
Planning rules from the Planning Portal, garage conversion planning permission. Building regulations from the Planning Portal: when approval is needed, in-fill garage door, flooring and ventilation. Planning fees from GOV.UK, fees for planning applications. Fire escape and alarms from Approved Document B, Volume 1: Dwellings, 2019 edition incorporating 2020, 2022 and 2025 amendments: paragraphs 1.2 to 1.4, 1.8, 2.1, 2.10, 2.11, 5.6 and 5.7. Insulation from Approved Document L, Volume 1: Dwellings, 2021 edition incorporating 2023 amendments: paragraphs 4.11 to 4.13, 11.6 and 11.7, Tables 4.2 and 4.3.
Heating costs from our heat model, built on the DESNZ National Energy Efficiency Data-Framework 2026, with energy prices from the Ofgem price cap for October to December 2026. Full method on our methodology and data sources pages.