Bedroom extensions in Runcorn
A bedroom extension in Runcorn 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 RuncornFrom £24,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsWA7, WA8
Included in a typical project
- Heating extended to the new rooms
- Fire safety: escape windows and smoke alarms to building regulations
- Structure, roof, insulation and finish
- En-suite drainage and ventilation design
- Layout options: two-storey, over-garage or ground floor
- Planning drawings and application
Guide prices for Runcorn
Labour and material costs vary across the UK, so for Runcorn we use our North West England factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Runcorn: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Covering Runcorn
Across WA7, WA8, we can visit, measure and advise. We also work in nearby Widnes (1 mile), Warrington (7 miles), Ellesmere Port (8 miles), Northwich (10 miles).
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.
Planning and approvals in Runcorn
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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 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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about bedroom extensions
How long does a bedroom extension take to build in Runcorn?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Runcorn, 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 Runcorn?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
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.
Book a free site visit in Runcorn
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.