Bedroom extensions across Lancaster
Lancaster homeowners can use us for the whole bedroom extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in LancasterFrom £24,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsLA1, LA4

Is a bedroom extension right for your house?
- Homeowners who want an en-suite master bedroom
- Growing families
- Multi-generational households
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
Local to Lancaster
We cover Lancaster and the postcode districts LA1, LA4. Nearby, we also take on projects in Morecambe (3 miles), Fleetwood (12 miles), Thornton-Cleveleys (15 miles), Poulton-le-Fylde (17 miles).
Ulverston, in Cumbria, is roughly 16 miles from Lancaster and also on our list. 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.
Will the council need to approve it?
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 Lancaster address depends on its history and any designations, which is why we check it at the first visit.
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).
Bedroom extension prices in Lancaster
Labour and material costs vary across the UK, so for Lancaster we use our North West England factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Lancaster: £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 |
For a figure based on your own dimensions, use our guide-price tool.
How the project works
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 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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Bedroom extension questions answered
Will my neighbours in Lancaster 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.
Do you cover all of Lancaster?
Yes. We cover Lancaster and the surrounding parts of Lancashire. Site visits are free and there is no obligation.
Who do I contract with for a bedroom extension in Lancaster?
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.
Does an en-suite need a window?
No, but it needs mechanical extraction that meets the building regulations. We design the duct route at the drawing stage.
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 Lancaster
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.