New Barnet, Greater London
Kitchen-diner rear extension in New Barnet
Thinking about a kitchen-diner rear extension in New Barnet? An open-plan kitchen, dining and family room that opens straight onto the garden. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover New Barnet (EN4, EN5 and N20) as part of our Greater London work. A kitchen-diner is often the reason people in New Barnet extend: the back kitchen in 1930s semis and post-war houses 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 New Barnet?
In New Barnet, 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 New Barnet?
Whether your kitchen-diner rear extension in New Barnet needs a planning application depends on its size, your house and any local restrictions.
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 New Barnet like to extend?
New Barnet is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.
How a kitchen-diner rear extension in New 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.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Kitchen-diner rear extensions near New Barnet
Neighbouring places we cover include East Barnet (0.6 miles) and Barnet (1.1 miles).
- Kitchen-diner rear extension in East Barnet
- Kitchen-diner rear extension in Barnet
- Kitchen-diner rear extension in Cockfosters
- Kitchen-diner rear extension in Hadley Wood
- Kitchen-diner rear extension in Totteridge
Other work in New Barnet:
FAQ
Kitchen-diner rear extension questions in New Barnet
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Is the site visit in New Barnet free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Should the sink face the garden?
If the plan allows, an island sink or hob facing the glass is a common choice. It needs a floor-level drain run, which is easy to lay in a new slab.
How long does a rear extension take to build in New 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 you match the brick or stone on my New Barnet house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do you handle building control in New Barnet?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.