High Wycombe, Buckinghamshire
Kitchen-diner rear extension in High Wycombe
We plan and build kitchen-diner rear extensions for homeowners in High Wycombe. 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.
High Wycombe and its postcode districts HP11, HP12 and HP13 are part of our Buckinghamshire coverage. A kitchen-diner is often the reason people in High Wycombe extend: the back kitchen in inter-war semis and 1960s estates is rarely big enough for a table.
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 High Wycombe?
A kitchen-diner rear extension in High Wycombe is priced at £2,130–£3,470 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
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 High Wycombe?
Whether your kitchen-diner rear extension in High Wycombe needs a planning application depends on its size, your house and any local restrictions.
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.
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 High Wycombe like to extend?
Around High Wycombe the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.
How a kitchen-diner rear extension in High Wycombe 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.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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 High Wycombe
From High Wycombe, the nearest places we also cover are Marlow (4.3 miles) and Beaconsfield (4.5 miles).
- Kitchen-diner rear extension in Marlow
- Kitchen-diner rear extension in Beaconsfield
- Kitchen-diner rear extension in Amersham
- Kitchen-diner rear extension in Amersham on the Hill
- Kitchen-diner rear extension in Burnham
Other work in High Wycombe:
FAQ
Kitchen-diner rear extension questions in High Wycombe
Is the site visit in High Wycombe free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.
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.
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.
How long does a rear extension take to build in High Wycombe?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do you handle building control in High Wycombe?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.