Croxley Green, Hertfordshire
Kitchen-diner rear extension in Croxley Green
An open-plan kitchen, dining and family room that opens straight onto the garden. If you live in Croxley Green 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.
Croxley Green sits in Hertfordshire, with postcode districts including WD1, WD3 and WD18. We usually keep the working kitchen where the old one was and put the dining table in the new space by the doors, which suits most Croxley Green homes.
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 Croxley Green?
In Croxley Green, our guide for a kitchen-diner rear extension is £2,010–£3,290 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a kitchen-diner rear extension in Croxley Green?
Planning for a kitchen-diner rear extension in Croxley Green follows the English householder rules.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Croxley Green like to extend?
Post-war semis and newer estates are typical of Croxley Green, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a kitchen-diner rear extension in Croxley Green comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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 Croxley Green
We also build kitchen-diner rear extensions in nearby Batchworth (0.6 miles) and Rickmansworth (1.2 miles).
- Kitchen-diner rear extension in Batchworth
- Kitchen-diner rear extension in Rickmansworth
- Kitchen-diner rear extension in Northwood
- Kitchen-diner rear extension in West Watford
- Kitchen-diner rear extension in Watford
Other work in Croxley Green:
FAQ
Kitchen-diner rear extension questions in Croxley Green
Is the site visit in Croxley Green free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How much does a kitchen-diner rear extension cost in Croxley Green?
As a guide, £2,010–£3,290 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £24,000–£39,500 at that rate. Your written price follows the survey.
Do you fit the kitchen?
Yes, whether you buy it yourself or we supply it. We take the measurements from the built shell, not the drawings.
Do I need planning permission for a rear extension in Croxley Green?
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.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
How long does a rear extension take to build in Croxley Green?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.