Bedroom extensions in Redhill
Redhill homeowners can use us for the whole bedroom extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in RedhillFrom £29,000 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsRH1, RH2

Planning rules that apply in Redhill
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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).
Is a bedroom extension right for your house?
- Growing families
- Multi-generational households
- Homeowners who want an en-suite master bedroom
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.
Bedroom extension prices in Redhill
Prices below are for Redhill, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Redhill: £1,790 to £3,580 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £29,000 – £35,500 | £29,000 – £38,000 | £32,000 – £43,500 |
| Bedroom and en-suite 18 m² | £32,000 – £39,500 | £38,000 – £49,500 | £48,000 – £65,000 |
| Two rooms 30 m² | £53,500 – £66,000 | £63,500 – £82,500 | £80,500 – £108,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in Redhill
Postcode districts we cover around Redhill include RH1, RH2. The same team covers Reigate (2 miles), Horley (5 miles), Caterham (5 miles), Banstead (6 miles), all within easy reach.
Coulsdon, in Greater London, is roughly 6 miles from Redhill and also on our list. The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
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
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Redhill
Will my neighbours in Redhill 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.
Do you cover all of Redhill?
Yes. We cover Redhill and the surrounding parts of Surrey. Site visits are free and there is no obligation.
Do I need building regulations approval in Redhill?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
Book a free site visit in Redhill
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.