Watford, Hertfordshire
Kitchen-diner rear extension in Watford
For homes in Watford, 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.
Watford and its postcode districts WD1, WD17, WD18 and WD24 are part of our Hertfordshire coverage. For Watford 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 Watford?
In Watford, 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 |
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 Watford?
The planning route for a kitchen-diner rear extension in Watford 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. 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 Watford like to extend?
Post-war semis and newer estates are typical of Watford, 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 Watford 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Watford
We also build kitchen-diner rear extensions in nearby West Watford (0.9 miles) and Bushey (1.7 miles).
- Kitchen-diner rear extension in West Watford
- Kitchen-diner rear extension in Bushey
- Kitchen-diner rear extension in North Watford
- Kitchen-diner rear extension in Croxley Green
- Kitchen-diner rear extension in Northwood
Other work in Watford:
FAQ
Kitchen-diner rear extension questions in Watford
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.
Do you handle building control in Watford?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
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.
What postcode areas do you cover around Watford?
Including WD1, WD17, WD18, WD24 and WD25, and the surrounding Hertfordshire area.
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.
Do I need planning permission for a rear extension in Watford?
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.