Garage Conversions
Transform your underused garage into valuable living space. From single-car integral conversions to full detached garage transformations — we deliver quality builds that feel like they were always part of the house.
Your Garage Is Probably Your Cheapest Extension
Most garages in the UK aren't used for cars. They're full of old furniture, bikes, Christmas decorations, and boxes that haven't been opened since the last move. Meanwhile, you need another bedroom, a home office, or a proper playroom — and the space is sitting right there, already built, with a roof and four walls.
A garage conversion is the most cost-effective way to add habitable space to your home. You're not building from scratch — the structure already exists. There are no foundations to dig, no roof to construct, no external walls to raise. The shell is there. We insulate it, finish it, and bring it up to building regulations standard so it becomes a proper room: warm, dry, and indistinguishable from the rest of your house.
We carry out garage conversions across Buckinghamshire the UK, from Victorian terraces in London with integral garages to 1970s detached homes in Manchester and Birmingham with oversized double garages. Each one gets the same attention to detail — proper insulation, damp-proofing, ventilation, and quality finishes. No bodge jobs, no cutting corners on the bits you can't see.
Why Convert Instead of Extend?
A garage conversion typically costs 40–60% less per square metre than a traditional house extension. A standard single garage gives you roughly 15m² of new living space — equivalent to a good-sized bedroom, home office, or snug — for a fraction of what you'd spend building that space from the ground up.
There's also far less disruption. A straightforward conversion takes 3–5 weeks on site compared to 10–14 weeks for a single-storey extension. No groundwork, no scaffolding, no weeks of blockwork going up. Your garden stays intact. Your neighbours stay happy.
From a property value perspective, a well-finished garage conversion adds 10–15% to your home's value. In areas with strong demand — particularly in London, Bristol, and Leeds — that extra bedroom or home office is worth far more than a parking space. Estate agents consistently report that buyers prefer converted garages over unused ones, especially when the conversion is done to a high standard with proper building regulations sign-off.
And here's what catches most people out: if you ever need the parking space back, a conversion can be reversed. It's not common, but knowing it's possible gives some homeowners the confidence to go ahead.
Types of Garage Conversion
The approach depends on your garage type, what you want to use the space for, and your budget. Here are the four main types we build.
Integral Garage Conversion
An integral garage sits within the main footprint of your house — typically at the front, with a bedroom or living room above. This is the simplest and cheapest conversion because the garage already shares walls, a ceiling, and often heating infrastructure with the rest of the house. The main work involves replacing the garage door with a window and insulated wall, insulating the floor, upgrading electrics, and finishing to match your existing rooms. Fire safety is critical here: Approved Document Part B requires a 30-minute fire-resistant barrier between the converted space and any habitable room above.
Attached Garage Conversion
An attached garage shares one wall with the house but sits as a separate structure alongside it. Conversion involves the same insulation and finishing work as an integral conversion, but you've also got the opportunity to knock through the shared wall to create an open-plan connection with the existing room. This typically requires a steel beam (RSJ) to support the load above — budget £1,200–£2,500 for the steel and installation. Sound insulation (Part E) is required if the garage adjoins a neighbouring property. You'll need to address damp-proofing on all external walls, as garages are rarely built with cavity wall insulation.
Detached Garage Conversion
Detached garages sit away from the main house, which makes them ideal for self-contained spaces — home offices, studios, guest suites, or annexes. The conversion work is more extensive because all four walls, the floor, and the roof need full insulation. You'll also need to run utilities from the main house: electricity, water (if adding a WC or kitchen), and drainage. Running a water supply and waste pipe to a detached garage typically costs £3,000–£6,000 depending on distance and ground conditions. The upside is total independence from the main house — no noise transfer, no disruption to your existing layout.
Partial Garage Conversion
If you still want some storage or a utility area, a partial conversion splits your garage into two zones: one converted into habitable space, the other retained for storage, a workshop, or laundry. We build an insulated stud wall to divide the space, with a proper fire-rated door between the two areas if required. This works particularly well with double garages — you convert one bay into a bedroom or office and keep the other for bikes, tools, or a tumble dryer. Costs are lower because you're converting a smaller area, but you still get the building regs sign-off on the habitable portion.
Garage Conversion Costs in 2026
Garage conversions are one of the best-value home improvements you can make. Here's what to budget based on the level of work involved. All prices include VAT.
Simple Conversion
£8,000 – £15,000
Covers the essentials: replacing the garage door with an insulated wall and window, floor insulation (rigid board over the existing slab), wall insulation (50mm PIR board or stud wall with mineral wool), basic electrics (lighting, sockets, consumer unit upgrade), plastering, and decoration. No plumbing, no wall removal, no structural changes. This level suits a bedroom, home office, or playroom where you don't need water. Typical timescale: 3–4 weeks on site.
Full Conversion with Utilities
£15,000 – £25,000
Everything in the simple conversion plus plumbing (radiators, towel rail, or underfloor heating), a WC or shower room, structural wall removal with steel beam to connect to the house, upgraded electrics, and quality finishes (engineered timber or porcelain tile flooring, fitted storage). This is the most popular option — it creates a proper room that integrates seamlessly with your home. Budget an extra £2,000–£4,000 if you want underfloor heating throughout.
High-Spec Conversion
£25,000 – £40,000+
A premium finish with bespoke joinery, en-suite bathroom, bi-fold or French doors to the garden, underfloor heating, smart lighting, acoustic insulation, and high-end materials throughout. Popular for garden-facing garages where you can open up the rear wall with glazing. Also covers detached garage conversions needing full utility runs and extensive insulation. This level is common for home studios, therapy rooms, and self-contained guest suites.
What's Not Included
Additional Costs
Building regulations application: £300–£700. Structural engineer (if removing walls): £300–£600. Architect drawings (if needed): £400–£800. Skip hire: £250–£400. New driveway surface where the garage door was: £500–£2,000 depending on material. These are typical add-ons that sit outside the main build cost. We'll itemise everything in your quote so there are no surprises.
Regional Price Differences
As with all building work, location matters. Labour rates and skip costs vary significantly across the UK. For more detail, see our garage conversion cost guide.
London & South East: £12,000–£30,000+
Highest labour rates. Parking permits for skips, congestion charges on deliveries, and tight access in terraced streets all push costs up. London projects typically sit 20–30% above the national average.
Midlands & North West: £8,000–£22,000
Birmingham, Manchester, Liverpool — competitive trade rates and good material availability keep costs reasonable.
North East & Yorkshire: £7,000–£20,000
Leeds, Sheffield, Newcastle — typically the lowest conversion costs in England, though material prices are broadly similar nationwide.
South West & Wales: £9,000–£24,000
Bristol and Bath are at the higher end. Rural locations can add to delivery and trade travel costs.
Planning Permission & Building Regulations
Planning Permission — Usually Not Required
A garage conversion is generally classed as permitted development because you're changing the use of an existing structure, not extending the building's footprint or increasing its volume. You're not building anything new — you're upgrading what's already there.
However, there are exceptions. You will need planning permission if:
Listed buildings: Any alteration to a listed building requires listed building consent, and most councils will want a full planning application as well.
Conservation areas: Some conservation area designations restrict changes to the front elevation — and since most garages face the street, replacing the garage door with a wall and window can trigger a planning requirement.
Conditions on original permission: Some newer estates have planning conditions requiring the garage to be retained for parking. Check your original planning permission or ask your local authority.
Flats and maisonettes: Permitted development rights don't apply to flats. If your garage is part of a block or a shared structure, you'll need planning permission and possibly freeholder consent.
Even if you don't need planning permission, it's worth applying for a Certificate of Lawful Development (around £100–£200). This confirms the conversion is lawful under permitted development, which is useful when you come to sell the property — solicitors always ask for it.
Building Regulations — Always Required
Regardless of whether you need planning permission, building regulations approval is mandatory for a garage conversion. You're changing the use from a non-habitable space to a habitable one, and the building must meet current standards. The key parts are:
Part B — Fire Safety: This is particularly important for integral garages. The existing 30-minute fire separation between the garage and the house must be maintained or upgraded. Fire doors (FD30) are required between the converted space and the hallway. Smoke alarms must be fitted on every floor of the house, interlinked to mains power with battery backup.
Part L — Conservation of Energy: The converted space must meet current thermal performance standards. Walls need a U-value of 0.28 W/m²K or better (0.18 for new elements), the floor 0.22 W/m²K, and the roof 0.16 W/m²K if exposed. This usually means 75–100mm of PIR insulation on walls and floor, and 150mm+ in the roof space. Windows must be double-glazed to a minimum U-value of 1.4 W/m²K.
Part E — Sound Insulation: Required if the garage shares a wall with a neighbouring property (common on semi-detached and terraced houses). The party wall must achieve minimum airborne sound insulation values — typically requiring an independent stud wall with acoustic mineral wool on your side.
Part P — Electrical Safety: New circuits and any work in the converted space must be signed off by a Part P registered electrician or inspected by building control.
Part F — Ventilation: Habitable rooms require adequate ventilation — trickle vents in windows plus an extract fan if there's a WC or shower room. Purge ventilation (opening windows) must provide at least 1/20th of the floor area.
We submit the building regs application, coordinate all inspections, and ensure you receive a completion certificate at the end. This certificate is essential for selling your home — without it, a buyer's solicitor will flag it, and it can delay or derail a sale.
How a Garage Conversion Works
From first survey to handing over a finished room, here's what happens at each stage.
Survey & Design
1–2 weeks. We assess the garage structure, check the floor level relative to the house, identify any damp issues, confirm electrics capacity, and measure up. If wall removal is planned, our structural engineer specifies the steelwork. Drawings are prepared for the building regs application.
Approvals & Prep
2–4 weeks. Building regulations application submitted (full plans or building notice). Materials ordered. If you're applying for a Certificate of Lawful Development, this runs in parallel. We confirm start dates once approvals are in hand.
Build & Finish
3–6 weeks. Garage door removed, new wall built with window. Floor raised and insulated (typically 100mm PIR over DPM on the existing slab). Walls insulated and plasterboarded. First fix electrics and plumbing. Plastering, second fix, decoration, flooring. Final building control inspection and completion certificate issued.
Getting the Build Right
Floor Insulation & Damp-Proofing
Garage floors are typically a concrete slab with no insulation and no damp-proof membrane (DPM). To make the space habitable, we lay a new DPM across the entire floor, then build up with rigid insulation board (typically 75–100mm Celotex or Kingspan to achieve a U-value of 0.22 W/m²K or better), followed by a chipboard or plywood deck and your chosen flooring.
This raises the floor level by 100–150mm. In most integral garages, the floor already sits lower than the rest of the house (usually one or two brick courses down), so this build-up actually brings the finished floor level to match the house — which is ideal. If the garage floor is already level with the house, we may need to dig down or use thinner insulation boards to avoid creating a step up.
Damp is the biggest risk in garage conversions. Garages are built to lower standards than habitable rooms — they often have no cavity wall construction, no DPC, and concrete floors that wick moisture. We address this with DPM on the floor, cavity membrane on walls where there's no existing DPC, and proper ventilation to prevent condensation. If there's evidence of rising damp, we install a new chemical DPC at a cost of £40–£80 per linear metre.
Wall Insulation
Garage walls typically need insulating to meet Part L. There are two main approaches:
Insulated dry-lining: PIR insulation boards (50–75mm) bonded directly to the existing walls with adhesive, then skimmed or plasterboarded. Quick and space-efficient — you lose only 60–90mm of room width. Works well on solid walls in good condition.
Stud wall with mineral wool: A timber frame built against the existing wall, packed with mineral wool insulation, then plasterboarded. Takes up more space (100–120mm) but gives better acoustic performance and allows for services (electrics, plumbing) to run inside the wall. We use this on walls with damp issues (the cavity allows airflow behind the insulation) and where soundproofing is needed (Part E compliance on party walls).
Replacing the Garage Door
The front wall is the biggest change visually. We remove the garage door and frame, then build a new insulated wall with a window (or French doors if the garage opens onto a garden). The new wall must match the existing building in materials and appearance — brick to match, render to match, or stone to match.
The structural lintel above the old garage door opening usually spans the full width. We leave this in place — it's supporting the wall above — and build the new wall beneath it. If you want a smaller window than the original opening, we fill in the sides with matching brickwork and set the window centrally.
External finishes matter. A visible patch of new brickwork that doesn't match the original is the hallmark of a cheap conversion. We source matching bricks (or reclaimed bricks from architectural salvage yards) and use mortar that matches the original colour and profile. On rendered garages, we re-render the entire front elevation so there's no visible join.
Steel Beam for Wall Removal
If you want to open up the garage into the existing house — creating a through-room rather than a separate space — you'll need a structural steel beam (RSJ) to replace the load-bearing wall. This is the most disruptive part of the job but makes a dramatic difference to how the space feels.
A structural engineer calculates the beam size based on the load above (roof, first-floor wall, bedroom furniture). Typical steel sizes for a single garage opening are 152×152mm or 203×133mm UC sections. The beam sits on padstones at each end, which distribute the load into the supporting walls. Installation takes 1–2 days: temporary props go in, the wall comes out, the steel goes in, then everything is made good.
Budget £1,200–£2,500 for the steel beam, padstones, and installation. Add the structural engineer's fee (£300–£600) on top. It's a significant cost, but it transforms the garage from a separate room into an extension of your living space — and it's what separates a professional conversion from a DIY job.
Roof & Ceiling Insulation
If the garage has a pitched roof with a loft space above, we insulate at ceiling level — 300mm of mineral wool between and over the joists achieves a U-value well within Part L requirements. If the garage has a flat roof or a vaulted ceiling (no loft space), we insulate between the rafters with rigid PIR board (100–120mm) and add a vapour barrier before plasterboarding. Flat roofs often need upgrading to a warm-deck construction to prevent condensation, which may involve replacing the existing roof covering with modern insulation and a single-ply membrane.
Other Services You Might Need
A garage conversion often sparks ideas for other improvements. Many clients combine projects to save on setup costs.
House Extensions
If a garage conversion doesn't give you quite enough space, a rear or side extension might be the next step. We can combine a garage conversion with an extension for maximum impact — particularly effective on properties where the garage adjoins the kitchen area.
Loft Conversions
Converting both your garage and your loft simultaneously can transform a three-bed semi into a five-bed home. We manage both projects in parallel to minimise disruption and cost.
Bathroom Renovations
Adding an en-suite or WC to your garage conversion? See our bathroom renovation page for detailed guidance on wet room tanking, soil stack connections, and specification levels.
Structural Work
If your conversion involves removing load-bearing walls, installing steel beams, or addressing foundation issues, our structural work page covers what's involved and what it costs.
Garage Conversion Questions
Common questions from homeowners considering a garage conversion. If yours isn't answered here, get in touch — we're happy to help.
Common Questions
Details regarding our process, planning constraints, and project timelines.
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