Extensions over a garage in Christchurch: design, approvals and build
We design and build over-garage extensions for houses in Christchurch, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in ChristchurchFrom £24,000 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsBH5, BH6, BH7, BH23
Extensions in and around Christchurch
Postcode districts we cover around Christchurch include BH5, BH6, BH7, BH23. The same team covers Bournemouth (4 miles), Ferndown (7 miles), Poole (9 miles), Wimborne Minster (10 miles), all within easy reach.
New Milton, in Hampshire, is roughly 5 miles from Christchurch and also on our list. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
What is included
- New floor structure, walls and roof
- Insulation, electrics, heating and finish
- Design and householder planning application
- Structural survey of garage walls and foundations
- Strengthening or rebuilding the garage walls if needed
- Opening into the existing first floor
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.
Guide prices for Christchurch
These guide figures apply our South West England adjustment (×1.02) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Christchurch: £1,840 to £3,470 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £24,000 – £30,000 | £25,500 – £33,500 | £33,000 – £42,000 |
| Over a large single garage 16 m² | £29,000 – £36,000 | £34,000 – £44,500 | £44,000 – £55,500 |
| Over a double garage 24 m² | £44,000 – £54,000 | £51,000 – £66,500 | £66,000 – £83,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in Christchurch?
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.
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).
Our process, step by step
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Over-garage extension questions answered
Will my neighbours in Christchurch 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 Christchurch?
Yes. We cover Christchurch and the surrounding parts of Dorset. Site visits are free and there is no obligation.
Who do I contract with for an over-garage extension in Christchurch?
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.
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 Christchurch
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.