Bedroom extensions in New Cross
Planning a bedroom extension in New Cross? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide price in New CrossFrom £33,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSE4, SE8, SE10, SE14, SE15
Do I need planning permission in New Cross?
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 New Cross 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).
Is a bedroom extension right for your house?
- Growing families
- Multi-generational households
- Homeowners who want an en-suite master bedroom
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.
How much does a bedroom extension cost in New Cross?
Labour and material costs vary across the UK, so for New Cross we use our London factor (×1.3). The ranges include VAT and exclude design, structural and council fees.
Typical rates in New Cross: £2,080 to £4,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £33,500 – £41,500 | £33,500 – £44,000 | £37,000 – £50,000 |
| Bedroom and en-suite 18 m² | £37,000 – £46,000 | £44,000 – £57,500 | £56,000 – £75,000 |
| Two rooms 30 m² | £62,000 – £76,500 | £74,000 – £96,000 | £93,500 – £125,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in New Cross
Our survey diary covers New Cross, including SE4, SE8, SE10, SE14, SE15, SE16. We also work in nearby Brockley (1 mile), Greenwich (1 mile), Peckham (1 mile), Blackheath (2 miles).
Just over the Kent border, Swanley is about 11 miles away. Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
Our process, step by step
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
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.
Questions people ask about bedroom extensions
Who do I contract with for a bedroom extension in New Cross?
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 New Cross?
Yes. We cover New Cross and the surrounding parts of Greater London. Site visits are free and there is no obligation.
Do I need building regulations approval in New Cross?
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.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
Book a free site visit in New Cross
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.