Keynsham, Somerset
Kitchen-diner rear extension in Keynsham
We plan and build kitchen-diner rear extensions for homeowners in Keynsham. An open-plan kitchen, dining and family room that opens straight onto the garden. Start with a free site visit, then a written price once the design is agreed.
Keynsham sits in Somerset, with postcode districts including BS31. 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 Keynsham 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 Keynsham?
For Keynsham we work from the South West England rate: £1,980–£3,220 per square metre of new floor, including VAT, standard specification. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £23,500–£38,500 |
| 4 m wide × 5 m deep (20 m²) | £39,500–£64,500 |
| 4 m wide × 6 m deep (24 m²) | £47,500–£77,500 |
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 Keynsham?
Planning for a kitchen-diner rear extension in Keynsham 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 Keynsham like to extend?
Stone-built and rendered houses are common around Keynsham, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.
How a kitchen-diner rear extension in Keynsham 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.
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 Keynsham
From Keynsham, the nearest places we also cover are Kingswood (2.7 miles) and Mangotsfield (5.1 miles).
- Kitchen-diner rear extension in Kingswood
- Kitchen-diner rear extension in Mangotsfield
- Kitchen-diner rear extension in Bristol
- Kitchen-diner rear extension in Bishopsworth
- Kitchen-diner rear extension in Bath
Other work in Keynsham:
FAQ
Kitchen-diner rear extension questions in Keynsham
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.
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.
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 Keynsham?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What postcode areas do you cover around Keynsham?
Including BS31, and the surrounding Somerset 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.