First-floor extensions in Cleveleys

Useful details for planning a first-floor extension in Cleveleys.

Postcode districts: FY5
County / area: Lancashire, England
Price region: North West England
Guide price: £24,000–£34,500 (£1,710–£2,470 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Thornton-Cleveleys (0.8 miles), Fleetwood (3.5 miles), Poulton-le-Fylde (3.8 miles)
Distance to Preston: about 15.8 miles
First visit: Free, no obligation

About a first-floor extension

A first-floor extension is a new upstairs room built on top of an existing single-storey part of your house, such as a rear kitchen extension, a utility or a side annexe. It adds a bedroom, bathroom or study without enlarging the footprint. Whether it works depends mainly on whether the walls and foundations below can carry the extra load.

Around Cleveleys we also work in Thornton-Cleveleys, Fleetwood and Poulton-le-Fylde, and across the rest of Lancashire. Postcode district in and near Cleveleys: FY5.

What it costs in Cleveleys

A guide price for Cleveleys: around £24,000–£34,500 for 4 m × 3.5 m of new first-floor space (14 m²). That works out at £1,710–£2,470 per m² of new floor space, including VAT at 20%. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	4 m × 3.5 m of new first-floor space (14 m²)
Essential	£1,570–£2,270 per m²	£22,000–£32,000
Standard	£1,710–£2,470 per m²	£24,000–£34,500
Premium	£2,050–£2,960 per m²	£28,500–£41,500

Planning and building regulations in Cleveleys

In England, adding a first floor turns a single-storey extension into one of more than one storey. To be permitted development, the extension as a whole must go no more than 3 m beyond the rear wall of the original house and stay at least 7 m from the rear boundary, with matching materials and roof pitch. Over a side extension it always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Cleveleys homes

Escape and fire safety

A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.

Replacing the flat roof

The existing roof usually comes off and is replaced by a new first-floor structure. The room below is exposed for a short time, so we plan temporary weatherproofing and sequence the work to keep the kitchen or living room usable for as long as possible.

How we'd run your project

Look at the house
We start in Cleveleys with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Cleveleys.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about first-floor extensions in Cleveleys

Do I need planning permission for a first-floor extension in Cleveleys?

Cleveleys is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Cleveleys?

We cover Cleveleys (FY5) and nearby places including Thornton-Cleveleys, Fleetwood and Poulton-le-Fylde, plus the rest of Lancashire. The first site visit is free.

Who handles building regulations for a project in Cleveleys?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

What happens to the room below while the first floor is built?

The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.

Can I build on top of my existing single-storey extension?

Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.

Nearby

Close to Cleveleys? We work across the area, including:

Other extensions in Cleveleys

All two-storey extension services in Cleveleys · First-floor extensions across Lancashire

Tell us about your house in Cleveleys and we'll call you back to arrange a free, no-obligation visit.