Friern Barnet, Greater London
Kitchen-diner rear extension in Friern Barnet
For homes in Friern Barnet, a kitchen-diner rear extension is often the simplest way to gain space without moving. An open-plan kitchen, dining and family room that opens straight onto the garden. We take it from survey to completion certificate.
Friern Barnet and its postcode districts N11, N12 and N20 are part of our Greater London coverage. A kitchen-diner is often the reason people in Friern Barnet 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 Friern Barnet?
Guide prices for a kitchen-diner rear extension in Friern Barnet start from our London rate of £2,470–£4,030 per square metre, including VAT. 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a kitchen-diner rear extension in Friern Barnet?
The planning route for a kitchen-diner rear extension in Friern Barnet is set by England's householder rules and your council.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part 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 Friern Barnet like to extend?
Much of Friern Barnet 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 Friern Barnet 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Friern Barnet
From Friern Barnet, the nearest places we also cover are Muswell Hill (1.7 miles) and Finchley (1.8 miles).
- Kitchen-diner rear extension in Muswell Hill
- Kitchen-diner rear extension in Finchley
- Kitchen-diner rear extension in Wood Green
- Kitchen-diner rear extension in Palmers Green
- Kitchen-diner rear extension in Totteridge
Other work in Friern Barnet:
FAQ
Kitchen-diner rear extension questions in Friern Barnet
Do I need planning permission for a rear extension in Friern Barnet?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
How long does a rear extension take to build in Friern Barnet?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Can I have underfloor heating?
Yes. Wet underfloor heating in the new screed is the usual choice, often with the old room's radiators kept or replaced.
Is the site visit in Friern Barnet free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.
How much does a kitchen-diner rear extension cost in Friern Barnet?
As a guide, £2,470–£4,030 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £29,500–£48,500 at that rate. Your written price follows the survey.