Bedroom extensions in Derby
Planning a bedroom extension in Derby? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in DerbyFrom £24,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsDE1, DE3, DE21, DE22, DE23
Do I need planning permission in Derby?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 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).
How much does a bedroom extension cost 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: £1,520 to £3,040 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £24,500 – £30,500 | £24,500 – £32,000 | £27,000 – £36,500 |
| Bedroom and en-suite 18 m² | £27,000 – £33,500 | £32,000 – £42,000 | £41,000 – £55,000 |
| Two rooms 30 m² | £45,500 – £56,000 | £54,000 – £70,000 | £68,000 – £91,500 |
For a figure based on your own dimensions, use our guide-price tool.
Working in 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).
For homes towards Nottinghamshire, Eastwood is around 9 miles away. Homes across the East Midlands often have usable side land or a driveway beside the house, which opens up side and wraparound options.
Included in a typical project
- Fire safety: escape windows and smoke alarms to building regulations
- Structure, roof, insulation and finish
- Heating extended to the new rooms
- Layout options: two-storey, over-garage or ground floor
- En-suite drainage and ventilation design
- Planning drawings and application
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
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
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a bedroom extension in Derby
Will my neighbours in Derby 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Derby, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a bedroom extension take to build in Derby?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
How much does a bedroom extension cost?
Our guide range is about £1,520 to £3,040 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £32,000 to £42,000 at standard spec, depending on whether it is part of a larger two-storey build.
Does an en-suite need a window?
No, but it needs mechanical extraction that meets the building regulations. We design the duct route at the drawing stage.
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.