Extensions over a garage in Redhill: design, approvals and build
Redhill 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 RedhillFrom £26,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsRH1, RH2

Is an over-garage extension right for your house?
- Homes where the landing can connect to the new room
- Detached and link-detached houses with an attached garage
- Families needing a bedroom without losing garden
Fitting the new room to the existing landing is the planning puzzle inside the house. We design the connection first, then the roof, so the extension does not end up with awkward steps or a corridor through a bedroom.
Local to Redhill
Across RH1, RH2, we can visit, measure and advise. The same team covers Reigate (2 miles), Horley (5 miles), Caterham (5 miles), Banstead (6 miles), all within easy reach.
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Planning and approvals in Redhill
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.
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).
Guide prices for Redhill
For Redhill we adjust our national guide rates by ×1.12, the factor we use for South East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Redhill: £2,020 to £3,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £26,500 – £33,000 | £28,000 – £36,500 | £36,000 – £46,000 |
| Over a large single garage 16 m² | £32,000 – £39,500 | £37,500 – £48,500 | £48,000 – £61,000 |
| Over a double garage 24 m² | £48,000 – £59,500 | £56,000 – £73,000 | £72,500 – £91,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Redhill
Who do I contract with for an over-garage extension in Redhill?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
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.
How long does an over-garage extension take to build in Redhill?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
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.
Can I keep using the garage during the build?
Usually not for parking. The garage roof is removed and the space below is used for access and props for part of the build.
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.