Windsor, Berkshire
Kitchen-diner rear extension in Windsor
Kitchen-diner rear extension in Windsor: an open-plan kitchen, dining and family room that opens straight onto the garden. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Windsor (SL4) as part of our Berkshire work. For Windsor 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 Windsor?
Guide prices for a kitchen-diner rear extension in Windsor start from our South East England rate of £2,130–£3,470 per square metre, including VAT. South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £25,500–£41,500 |
| 4 m wide × 5 m deep (20 m²) | £42,500–£69,500 |
| 4 m wide × 6 m deep (24 m²) | £51,000–£83,500 |
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 Windsor?
Whether your kitchen-diner rear extension in Windsor needs a planning application depends on its size, your house and any local restrictions.
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. 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 Windsor like to extend?
Commuter semis and detached houses make up much of Windsor, and longer gardens make England's prior approval route for deeper rear extensions worth considering.
How a kitchen-diner rear extension in Windsor 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.
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 Windsor
We also build kitchen-diner rear extensions in nearby Slough (1.8 miles) and Egham (4.1 miles).
- Kitchen-diner rear extension in Slough
- Kitchen-diner rear extension in Egham
- Kitchen-diner rear extension in Burnham
- Kitchen-diner rear extension in Staines
- Kitchen-diner rear extension in Stanwell
Other work in Windsor:
FAQ
Kitchen-diner rear extension questions in Windsor
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 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.
Can I add a utility room?
Often. A narrow utility or boot room along one side keeps the washing machine out of the open-plan space.
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 you match the brick or stone on my Windsor house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How long does a rear extension take to build in Windsor?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.