A garage conversion turns an integral or attached garage into a warm, habitable room by insulating the floor, walls and ceiling, replacing the garage door with a wall and window, and adding heating, lighting and finishes.
We take on a garage conversion throughout Stevenage and the surrounding SG1 and SG2 postcodes, as well as in Hitchin, Letchworth Garden City and Welwyn Garden City. The guide range for this work in the East of England is £12,500–£29,500 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £12,500–£29,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- SG1 and SG2
- Planning rules
- England
- Local area
- Hertfordshire
- Survey
- Free, with a written quote
What should you budget for a garage conversion in Stevenage?
The costs listed here are typical for a garage conversion around Stevenage and include VAT. They reflect labour and material costs in the East of England, about 5% above the national guide, giving a range of £12,500–£29,500. Exact pricing depends on your home, so we only fix it once a free site survey is done.
| Type of job | What it usually involves | Guide in Stevenage |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £10,500–£19,000 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £14,500–£26,000 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £23,000–£47,000 |
Expect these to shape the final quote:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Heating method and ventilation for the new room
- Window and door choices and the level of finishes
What do you get?
- Infilling the garage door opening with insulated wall and new window
- Foundation checks under the door opening and footings where needed
- Damp-proof membrane, insulated floor and screed or raised timber floor
- Insulated walls and ceiling built to building regulations
- New internal door or opening into the house
- Electrics, heating and ventilation by qualified trades, with certificates
Homes in Hertfordshire
Hertfordshire is home to the first garden cities, Letchworth and Welwyn Garden City, and the post-war new towns of Stevenage, Hatfield and Hemel Hempstead. Watford and St Albans have Victorian terraces and Georgian streets, interwar semis line the commuter suburbs, and brick-and-flint cottages appear in Chiltern villages to the west.
New-town and garden-city homes often suit extensions, window replacement and roofline renewal, though some garden-city estates have their own design guidance. Victorian terraces commonly take loft rooms and side-return extensions.
With that background in mind, here is how we typically handle a garage conversion for homes in Stevenage, from the first visit to the finished result.
Planning and building rules in Stevenage
Which rules apply depends on where you live. For Stevenage, the answer is England, and the points below reflect that; we verify them with the council before quoting.
In England, converting an attached or integral garage into a room usually needs no planning permission, unless a planning condition on your estate has removed permitted development rights (common on newer houses). Changing the garage door to a wall and window is generally fine.
Building Regulations approval is needed: foundations for the infill wall, a damp-proof course, insulation, ventilation and fire safety.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
We look at the job
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Written quote
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Plan and prepare
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
Build and hand over
Our trades complete a garage conversion while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Working with SK Home Improvements
Questions about a garage conversion in Stevenage
How long will a garage conversion take?
On a typical home, allow 2–6 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
How much does a garage conversion cost?
A typical single garage conversion costs £12,500–£29,500, depending on whether the garage is integral, attached or detached and what the room is for. Integral garages usually cost least because the walls and roof are already sound. Adding a shower room, upgrading a flat roof or levelling a sloping floor adds cost. As a guide, allow roughly £550–£1,100 per square metre plus fixed costs. We confirm a fixed price after the survey.
Can I keep some storage space?
Many people keep part of the garage for storage by building a dividing wall, leaving a smaller store at the front behind the existing door and converting the area behind into a room or utility. This keeps the look of the house unchanged and gives you somewhere for bikes and tools. The converted part still needs the same insulation, ventilation and fire separation.
Will I need building regulations approval?
A garage conversion needs building regulations approval because the space becomes a habitable room. Building control checks that the new wall in the door opening has proper foundations, that the floor has a damp-proof membrane and insulation, and that walls and ceiling meet insulation standards. Ventilation, fire safety and escape routes are also checked. In Scotland a building warrant is normally needed before work starts.
Do you cover Hitchin, Letchworth Garden City and Welwyn Garden City?
Yes. As well as Stevenage, we cover Hitchin, Letchworth Garden City and Welwyn Garden City and the rest of Hertfordshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Near Stevenage
If your address falls within SG1 and SG2, we cover it. The same goes for neighbouring Hitchin, Letchworth Garden City and Welwyn Garden City, which we include alongside Stevenage when arranging surveys and quotes.