Extensions over a garage in Kirkby: design, approvals and build
From the first sketch to final sign-off, we plan and build over-garage extensions in Kirkby and the surrounding Merseyside area.
- Guide price in KirkbyFrom £22,500 inc VAT
- PlanningHouseholder application needed
- Build time12–18 weeks on site
- Postcode districtsL9, L10, L11, L31, L32
Working in Kirkby
We cover Kirkby and the postcode districts L9, L10, L11, L31, L32, L33. Nearby, we also take on projects in Maghull (3 miles), Litherland (4 miles), Prescot (5 miles), Bootle (5 miles).
Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
How much does an over-garage extension cost in Kirkby?
Prices below are for Kirkby, using the North West England factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Kirkby: £1,710 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Over a single garage 12 m² | £22,500 – £28,000 | £23,500 – £31,000 | £30,500 – £39,000 |
| Over a large single garage 16 m² | £27,000 – £33,500 | £31,500 – £41,500 | £41,000 – £52,000 |
| Over a double garage 24 m² | £41,000 – £50,500 | £47,500 – £62,000 | £61,500 – £78,000 |
For a figure based on your own dimensions, use our guide-price tool.
Do I need planning permission in Kirkby?
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 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
When an over-garage extension makes sense
- Detached and link-detached houses with an attached garage
- Families needing a bedroom without losing garden
- Homes where the landing can connect to the new room
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
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about an over-garage extension in Kirkby
How long does an over-garage extension take to build in Kirkby?
On site, typically 12 to 18 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Do you cover all of Kirkby?
Yes. We cover Kirkby and the surrounding parts of Merseyside. Site visits are free and there is no obligation.
Who do I contract with for an over-garage extension in Kirkby?
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 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.
How much does a room over a garage cost?
Our guide range is about £1,710 to £3,230 per m² including VAT. A single-garage room of about 12 m² usually costs £23,500 to £31,000 at standard spec, more if the garage needs rebuilding.
Book a free site visit in Kirkby
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.