Extensions over a garage in Basingstoke: design, approvals and build
Our design and build teams take on over-garage extensions in Basingstoke, from the first measured survey through planning and building control to the finished room.
- Guide price in BasingstokeFrom £26,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsRG21, RG22, RG23, RG24, RG25
Working in Basingstoke
Our survey diary covers Basingstoke, including RG21, RG22, RG23, RG24, RG25. Neighbouring towns we cover include Alton (9 miles), Fleet (11 miles), Yateley (12 miles), Aldershot (14 miles).
Thatcham, in Berkshire, is roughly 12 miles from Basingstoke and also on our list. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
What should I budget for an over-garage extension in Basingstoke?
Labour and material costs vary across the UK, so for Basingstoke we use our South East England factor (×1.12). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Basingstoke: £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 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in Basingstoke
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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 is included
- New floor structure, walls and roof
- Strengthening or rebuilding the garage walls if needed
- Design and householder planning application
- Opening into the existing first floor
- Insulation, electrics, heating and finish
- Structural survey of garage walls and foundations
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.
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
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
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.
Questions people ask about over-garage extensions
Who do I contract with for an over-garage extension in Basingstoke?
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Basingstoke, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Basingstoke?
Yes. We cover Basingstoke and the surrounding parts of Hampshire. Site visits are free and there is no obligation.
How much does a room over a garage cost?
Our guide range is about £2,020 to £3,810 per m² including VAT. A single-garage room of about 12 m² usually costs £28,000 to £36,500 at standard spec, more if the garage needs rebuilding.
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 Basingstoke
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.