Forest Hill, Greater London
Kitchen-diner rear extension in Forest Hill
An open-plan kitchen, dining and family room that opens straight onto the garden. If you live in Forest Hill and want to know what a kitchen-diner rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Forest Hill is covered from our Greater London round, including SE4, SE6 and SE23. A kitchen-diner is often the reason people in Forest Hill extend: the back kitchen in Victorian and Edwardian terraces is rarely big enough for a table.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a kitchen-diner rear extension cost in Forest Hill?
In Forest Hill, our guide for a kitchen-diner rear extension is £2,470–£4,030 per square metre including VAT for a standard specification. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £29,500–£48,500 |
| 4 m wide × 5 m deep (20 m²) | £49,500–£80,500 |
| 4 m wide × 6 m deep (24 m²) | £59,500–£96,500 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a kitchen-diner rear extension in Forest Hill?
Whether your kitchen-diner rear extension in Forest Hill needs a planning application depends on its size, your house and any local restrictions.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Forest Hill like to extend?
Much of Forest Hill is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a kitchen-diner rear extension in Forest Hill comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Kitchen-diner rear extensions near Forest Hill
From Forest Hill, the nearest places we also cover are Crofton Park (0.5 miles) and Perry Vale (0.7 miles).
- Kitchen-diner rear extension in Crofton Park
- Kitchen-diner rear extension in Perry Vale
- Kitchen-diner rear extension in Catford
- Kitchen-diner rear extension in Ladywell
- Kitchen-diner rear extension in Brockley
Other work in Forest Hill:
FAQ
Kitchen-diner rear extension questions in Forest Hill
How long does a rear extension take to build in Forest Hill?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What postcode areas do you cover around Forest Hill?
Including SE4, SE6 and SE23, and the surrounding Greater London area.
Where does the cooker extraction go?
Through the new wall or roof, ducted to outside. Recirculating hoods are possible but less effective.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Is the site visit in Forest Hill free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.