Brentwood, Essex
Kitchen-diner rear extension in Brentwood
An open-plan kitchen, dining and family room that opens straight onto the garden. If you live in Brentwood 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.
Brentwood is covered from our Essex round, including CM13, CM14 and CM15. For Brentwood kitchens we plan the extraction route and the island drainage before the slab is poured, so nothing has to be chased in later.
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 Brentwood?
Guide prices for a kitchen-diner rear extension in Brentwood start from our East of England rate of £2,010–£3,290 per square metre, including VAT. 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 Brentwood?
Planning for a kitchen-diner rear extension in Brentwood follows the English householder rules.
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 Brentwood like to extend?
Brentwood mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a kitchen-diner rear extension in Brentwood comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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 Brentwood
Close by, we work in Harold Wood, about 3.6 miles away, and Emerson Park, about 4.5 miles away.
- Kitchen-diner rear extension in Harold Wood
- Kitchen-diner rear extension in Emerson Park
- Kitchen-diner rear extension in Billericay
- Kitchen-diner rear extension in Upminster
- Kitchen-diner rear extension in Hornchurch
Other work in Brentwood:
FAQ
Kitchen-diner rear extension questions in Brentwood
Do I need planning permission for a rear extension in Brentwood?
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.
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.
How big should a kitchen-diner be?
Around 25 to 35 m² for the combined kitchen, dining and seating areas suits most family homes. Your survey shows what fits the house.
How much does a kitchen-diner rear extension cost in Brentwood?
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.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
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.