Side extensions in Thornton-Cleveleys: design, approvals and build
We design and build side extensions for houses in Thornton-Cleveleys, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in Thornton-CleveleysFrom £20,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsFY2, FY5, FY6
Extensions in and around Thornton-Cleveleys
Postcode districts we cover around Thornton-Cleveleys include FY2, FY5, FY6. The same team covers Poulton-le-Fylde (3 miles), Fleetwood (4 miles), Blackpool (4 miles), Lytham St Annes (9 miles), all within easy reach.
Just over the Merseyside border, Southport is about 16 miles away. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
Do I need planning permission in Thornton-Cleveleys?
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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.
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 we take care of
- Windows, doors and finishes to match
- New openings through the side wall
- Planning route checked or application made
- Foundations near boundaries and any drains
- Structure, roof tied into the house
- Survey, design and street-view drawings
What should I budget for a side extension in Thornton-Cleveleys?
These guide figures apply our North West England adjustment (×0.95) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Thornton-Cleveleys: £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 |
For a figure based on your own dimensions, use our guide-price tool.
What happens next
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
We visit your Thornton-Cleveleys home, measure up, talk through what you want and check the planning position.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Side extension questions answered
Will my neighbours in Thornton-Cleveleys 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Thornton-Cleveleys, 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 I need building regulations approval in Thornton-Cleveleys?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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 Thornton-Cleveleys.
Book a free site visit in Thornton-Cleveleys
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.