House extensions in Formby
From a small utility to a two-storey addition, we take on house extensions throughout Formby, starting with a free visit and a planning check.
- Postcode districtsL37
- Price regionNorth West England (×0.95)
- Planning rulesEngland
- Site visitFree, no obligation
Areas we cover around Formby
Site visits are available across Formby (L37). The same team covers Maghull (6 miles), Southport (7 miles), Bootle (7 miles), Litherland (7 miles), Kirkby (9 miles), all within easy reach. Just over the Lancashire border, Ormskirk is about 8 miles away.
Guide prices for Formby
Use these Formby guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Kitchen extensions | 20 m² | £39,500 – £50,500 |
| Wraparound extensions | 25 m² | £54,500 – £69,000 |
| Conservatory replacement extensions | 14 m² | £28,500 – £37,000 |
| Orangery extensions | 16 m² | £42,500 – £53,500 |
| Double-storey extensions | 32 m² | £54,500 – £71,500 |
| Side return extensions | 11 m² | £25,000 – £31,500 |
| Extensions over a garage | 12 m² | £23,500 – £31,000 |
Choosing the right extension in Formby
Across the North West, terraced houses with small rear yards suit compact rear and side return extensions, while suburban semis have room for more.
Depending on the plot, double-storey extensions and side return extensions are often the strongest options, with kitchen extensions worth considering where there is room.
Planning and building control in Formby
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 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.
Applications are decided by the local planning authority (your district, borough or unitary council).
All extension types we build in Formby
- Orangery extensions · from £28,500
- Timber frame extensions · from £19,500
- Conservatory replacement extensions · from £19,000
- Wraparound extensions · from £34,000
- Flat roof extensions · from £19,500
- Side extensions · from £20,500
- Building regulations for extensions · from £850
- Annexe extensions · from £52,000
- Extension plans and drawings · from £1,100
- Double-storey extensions · from £36,000
- Bungalow extensions · from £24,500
- Porch extensions · from £3,800
- Bedroom extensions · from £24,500
- Side return extensions · from £17,000
- Single-storey rear extensions · from £19,500
- Extensions over a garage · from £22,500
- Glass box extensions · from £28,500
- Utility and boot room extensions · from £13,000
- Planning permission for extensions · from £300
- Kitchen extensions · from £25,500
- Home office extensions · from £15,000
- Pitched roof extensions · from £21,000
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Formby
How much does an extension cost in Formby?
Using our North West England factor (×0.95), a standard-spec single-storey extension of 20 m² is a guide £38,500 to £49,500 including VAT, and a 32 m² two-storey extension £54,500 to £71,500. Your written price follows the survey.
Do I need planning permission for an extension in Formby?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do you cover all of Formby?
Yes, including the surrounding parts of Merseyside. Site visits are free and there is no obligation.
Book a free site visit in Formby
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.