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.
If you have a garage conversion on your list for a property in Thornaby-on-Tees, we can help from the first measurements to the final clean-up. For a typical home, plan for 2–6 weeks on site, though larger or more complex jobs take longer. We cover postcodes TS5, TS16, TS17 and TS18 and nearby Stockton-on-Tees, Yarm and Billingham, and every quote we send is fixed for the scope described in it.
- Guide price
- £11,500–£26,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- TS5, TS16, TS17 and TS18
- Planning rules
- England
- Local area
- Stockton-on-Tees
- Survey
- Free, with a written quote
What should you budget for a garage conversion in Thornaby-on-Tees?
In Thornaby-on-Tees, guide figures for a garage conversion sit at £11,500–£26,500, VAT included. We set them using rates for Yorkshire and the Humber, currently about 6% below the national guide. The table shows what pushes a project towards either end of the range; your own price is set after a free survey.
| Type of job | What it usually involves | Guide in Thornaby-on-Tees |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £9,400–£17,000 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £13,000–£23,500 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £20,500–£42,500 |
Expect these to shape the final quote:
- Garage type: integral, attached or detached
- Whether a shower room or kitchenette is included
- 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
- Building control inspections and completion certificate
Local housing and a garage conversion
York has medieval timber-framed, Georgian and Victorian buildings, Harrogate has stone Victorian villas and terraces, and the Dales and Moors are built of limestone and sandstone, often under stone-slate or pantile roofs. Teesside towns within the county, such as Middlesbrough and Redcar, have Victorian red-brick terraces and post-war estates.
Dales and Moors properties often need lime pointing, roof repairs and window designs acceptable within a national park. Teesside brick terraces suit loft rooms and rear extensions, and estate homes commonly take garage conversions.
If your house in Thornaby-on-Tees fits one of these patterns, it helps us anticipate what a garage conversion will involve, though we always confirm the details on site.
Do you need permission in Thornaby-on-Tees?
Thornaby-on-Tees is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
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.
The four stages
We look at the job
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a garage conversion so the price reflects your home.
Written quote
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Dates and permissions
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
Build and hand over
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
How we work
Frequently asked questions
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Do I need planning permission for a garage conversion?
Whether a garage conversion needs planning permission depends on the works, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, converting an integral or attached garage is often permitted development where changes are mostly internal, unless a planning condition has removed those rights, which is common on newer estates. We check what applies before quoting.
Will the new room be warm enough?
A converted garage can be as warm as any other room in the house, provided the floor, walls and ceiling are insulated to current standards. Garages are usually built with single-skin walls and no insulation, so this work matters. Heating can come from a new radiator on your existing system, underfloor heating or an electric heater, depending on your boiler capacity. We advise on the most suitable option.
How much does a garage conversion cost?
A typical single garage conversion costs £11,500–£26,500, 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.
How much will a garage conversion cost in Thornaby-on-Tees?
As a guide, expect to pay £11,500–£26,500 including VAT for a garage conversion in Thornaby-on-Tees. That range is adjusted for Yorkshire and the Humber, which runs about 6% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Near Thornaby-on-Tees
If your address falls within TS5, TS16, TS17 and TS18, we cover it. The same goes for neighbouring Stockton-on-Tees, Yarm and Billingham, which we include alongside Thornaby-on-Tees when arranging surveys and quotes.

