Bedroom extensions in Thornton-Cleveleys: design, approvals and build
A bedroom extension in Thornton-Cleveleys starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in Thornton-CleveleysFrom £24,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsFY2, FY5, FY6
Planning and approvals in Thornton-Cleveleys
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.
The planning position for a specific Thornton-Cleveleys address depends on its history and any designations, which is why we check it at the first visit.
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.
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).
What is included
- Structure, roof, insulation and finish
- Planning drawings and application
- Heating extended to the new rooms
- En-suite drainage and ventilation design
Working in Thornton-Cleveleys
Across FY2, FY5, FY6, we can visit, measure and advise. Nearby, we also take on projects in Poulton-le-Fylde (3 miles), Fleetwood (4 miles), Blackpool (4 miles), Lytham St Annes (9 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 a bedroom extension cost in Thornton-Cleveleys?
Prices below are for Thornton-Cleveleys, 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 Thornton-Cleveleys: £1,520 to £3,040 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £24,500 – £30,500 | £24,500 – £32,000 | £27,000 – £36,500 |
| Bedroom and en-suite 18 m² | £27,000 – £33,500 | £32,000 – £42,000 | £41,000 – £55,000 |
| Two rooms 30 m² | £45,500 – £56,000 | £54,000 – £70,000 | £68,000 – £91,500 |
Try the guide-price tool to see a range for your own size and finish.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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.
Bedroom extension questions answered
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.
Who do I contract with for a bedroom extension in Thornton-Cleveleys?
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.
Do you cover all of Thornton-Cleveleys?
Yes. We cover Thornton-Cleveleys and the surrounding parts of Lancashire. Site visits are free and there is no obligation.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
How much does a bedroom extension cost?
Our guide range is about £1,520 to £3,040 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £32,000 to £42,000 at standard spec, depending on whether it is part of a larger two-storey build.
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.