Extensions over a garage across County Durham
Thinking about an over-garage extension for your County Durham home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide priceFrom £21,500 inc VAT
- PlanningHouseholder application needed
- Towns covered14
- Site visitFree, no obligation
Towns in County Durham
Planning rules that apply in County Durham
In England any side extension over one storey, including a room built over a side garage, needs a householder planning application. The fee is £548 from 1 April 2026 and councils aim to decide within 8 weeks.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for an over-garage extension in County Durham?
Labour and material costs vary across the UK, so for County Durham we use our North East England factor (×0.91). The ranges include VAT and exclude design, structural and council fees.
Typical rates in County Durham: £1,640 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £21,500 – £27,000 | £22,500 – £29,500 | £29,000 – £37,500 |
| Over a large single garage 16 m² | £26,000 – £32,500 | £30,500 – £39,500 | £39,000 – £50,000 |
| Over a double garage 24 m² | £39,000 – £48,500 | £45,500 – £59,000 | £58,500 – £74,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Included in a typical project
- Insulation, electrics, heating and finish
- Structural survey of garage walls and foundations
- New floor structure, walls and roof
- Strengthening or rebuilding the garage walls if needed
- Opening into the existing first floor
Covering County Durham
Towns we cover in County Durham include Darlington, Hartlepool, Stockton-on-Tees, Durham, Chester-le-Street, Billingham, Stanley, Consett. Across the North East, houses often have rear yards or modest gardens, so compact, well-lit single-storey extensions make the biggest difference.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Over-garage extension questions answered
Do you cover all of County Durham?
Yes, across the whole of County Durham. Site visits are free and there is no obligation.
How long does an over-garage extension take to build in County Durham?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Will my neighbours in County Durham be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Does building over a garage need planning permission?
In England and the rest of the UK, adding a storey over a side garage almost always needs a planning application, because two-storey side extensions are outside permitted development.
How much does a room over a garage cost?
Our guide range is about £1,640 to £3,090 per m² including VAT. A single-garage room of about 12 m² usually costs £22,500 to £29,500 at standard spec, more if the garage needs rebuilding.
Book a free site visit in County Durham
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.