Bedroom extensions across Wallington
Planning a bedroom extension in Wallington? 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 WallingtonFrom £33,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSM1, SM2, SM5, SM6
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.
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.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Extensions in and around Wallington
Across SM1, SM2, SM5, SM6, we can visit, measure and advise. Neighbouring towns we cover include Carshalton (1 mile), Sutton (2 miles), South Croydon (3 miles), Purley (3 miles).
Just over the Surrey border, Banstead is about 4 miles away. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
Who a bedroom extension suits
- 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.
How much does a bedroom extension cost in Wallington?
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Wallington: £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.
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
We visit your Wallington home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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.
Your questions about a bedroom extension in Wallington
How long does a bedroom extension take to build in Wallington?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Who do I contract with for a bedroom extension in Wallington?
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 I need building regulations approval in Wallington?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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 £2,080 to £4,160 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £44,000 to £57,500 at standard spec, depending on whether it is part of a larger two-storey build.
Book a free site visit in Wallington
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.