Birkenhead side extensions, designed and built
Thinking about a side extension for your Birkenhead home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in BirkenheadFrom £20,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsCH41, CH42, CH44, L1, L2
Planning rules that apply in Birkenhead
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
The planning position for a specific Birkenhead address depends on its history and any designations, which is why we check it at the first visit.
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).
When a side extension makes sense
- Detached and semi-detached houses with side land
- Homes needing a utility, study or ground-floor bedroom
- Houses where the rear garden is small
Guide prices for Birkenhead
Prices below are for Birkenhead, 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 Birkenhead: £1,660 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £20,500 – £25,500 | £23,000 – £30,500 | £29,500 – £39,000 |
| 3 m × 6 m 18 m² | £29,500 – £36,000 | £35,000 – £45,500 | £44,000 – £58,500 |
| 3 m × 8 m 24 m² | £39,500 – £48,000 | £46,500 – £60,500 | £59,000 – £78,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Covering Birkenhead
Site visits are available across Birkenhead (CH41, CH42, CH44, L1, L2, L3). The same team covers Liverpool (2 miles), Wallasey (3 miles), Bebington (3 miles), Bootle (5 miles), all within easy reach.
For homes towards Cheshire, Ellesmere Port is around 9 miles away. Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
From first visit to completion
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
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
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 Birkenhead
Do you cover all of Birkenhead?
Yes. We cover Birkenhead and the surrounding parts of Merseyside. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Birkenhead, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a side extension take to build in Birkenhead?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
Can I build a side extension without planning permission?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a planning application.
How much does a side extension cost?
Our guide range is about £1,660 to £3,230 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £35,000 to £45,500 in Birkenhead.
Book a free site visit in Birkenhead
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.