Extensions over a garage for homes in Derby
Derby homeowners can use us for the whole over-garage extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in DerbyFrom £22,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsDE1, DE3, DE21, DE22, DE23
Extensions in and around Derby
Our survey diary covers Derby, including DE1, DE3, DE21, DE22, DE23, DE24. Neighbouring towns we cover include Belper (7 miles), Ilkeston (8 miles), Heanor (8 miles), Ripley (8 miles).
Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
When an over-garage extension makes sense
- Detached and link-detached houses with an attached garage
- Homes where the landing can connect to the new room
- Families needing a bedroom without losing garden
Over-garage extension prices in Derby
These guide figures apply our East Midlands adjustment (×0.95) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Derby: £1,710 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £22,500 – £28,000 | £23,500 – £31,000 | £30,500 – £39,000 |
| Over a large single garage 16 m² | £27,000 – £33,500 | £31,500 – £41,500 | £41,000 – £52,000 |
| Over a double garage 24 m² | £41,000 – £50,500 | £47,500 – £62,000 | £61,500 – £78,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in Derby?
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.
The planning position for a specific Derby address depends on its history and any designations, which is why we check it at the first visit.
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.
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).
From first visit to completion
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Over-garage extension questions answered
Do you cover all of Derby?
Yes. We cover Derby and the surrounding parts of Derbyshire. Site visits are free and there is no obligation.
How long does an over-garage extension take to build in Derby?
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 Derby?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
How much does a room over a garage cost?
Our guide range is about £1,710 to £3,230 per m² including VAT. A single-garage room of about 12 m² usually costs £23,500 to £31,000 at standard spec, more if the garage needs rebuilding.
Book a free site visit in Derby
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.