Doncaster over-garage extensions, designed and built
A over-garage extension in Doncaster starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in DoncasterFrom £22,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsDN1, DN2, DN3, DN4, DN5
Planning and approvals in Doncaster
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 regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
What we take care of
- New floor structure, walls and roof
- Design and householder planning application
- Insulation, electrics, heating and finish
- Opening into the existing first floor
- Strengthening or rebuilding the garage walls if needed
Working in Doncaster
Our survey diary covers Doncaster, including DN1, DN2, DN3, DN4, DN5, DN12. We also work in nearby Adwick le Street (4 miles), Rawmarsh (10 miles), Dinnington (11 miles), Rotherham (11 miles).
Just over the West Yorkshire border, South Elmsall is about 8 miles away. Homes across Yorkshire and the Humber range from back-to-back and through terraces to large suburban semis, and extension options vary with them.
Guide prices for Doncaster
These guide figures apply our Yorkshire and the Humber adjustment (×0.94) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Doncaster: £1,690 to £3,200 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £22,500 – £28,000 | £23,500 – £30,500 | £30,000 – £38,500 |
| Over a large single garage 16 m² | £27,000 – £33,500 | £31,500 – £41,000 | £40,500 – £51,500 |
| Over a double garage 24 m² | £40,500 – £50,000 | £47,000 – £61,000 | £60,500 – £77,000 |
For a figure based on your own dimensions, use our guide-price tool.
How the project works
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
We visit your Doncaster home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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.
Common questions in Doncaster
Do you cover all of Doncaster?
Yes. We cover Doncaster and the surrounding parts of South Yorkshire. Site visits are free and there is no obligation.
How long does an over-garage extension take to build in Doncaster?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Do I need building regulations approval in Doncaster?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How much does a room over a garage cost?
Our guide range is about £1,690 to £3,200 per m² including VAT. A single-garage room of about 12 m² usually costs £23,500 to £30,500 at standard spec, more if the garage needs rebuilding.
Can my garage take the weight of a room on top?
Some can and some cannot. Many garages have a single-skin wall or shallow foundations. Our structural engineer checks this before we give a fixed price.
Book a free site visit in Doncaster
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.