Knowle, West Midlands
Kitchen-diner rear extension in Knowle
An open-plan kitchen, dining and family room that opens straight onto the garden. If you live in Knowle 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.
Knowle sits in the West Midlands, with postcode districts including B40. For Knowle 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 Knowle?
A kitchen-diner rear extension in Knowle is priced at £1,900–£3,100 per square metre including VAT as a guide, before kitchen fit-out and fees. The West Midlands is the baseline for our guide prices.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £23,000–£37,000 |
| 4 m wide × 5 m deep (20 m²) | £38,000–£62,000 |
| 4 m wide × 6 m deep (24 m²) | £45,500–£74,500 |
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 Knowle?
Whether your kitchen-diner rear extension in Knowle 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.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Knowle like to extend?
Red-brick terraces and 1930s semis make up much of Knowle. Many already have a small kitchen lean-to at the back, which a new rear extension usually replaces rather than adds to.
How a kitchen-diner rear extension in Knowle 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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 Knowle
Neighbouring places we cover include Solihull (2.9 miles) and Shirley (4.1 miles).
- Kitchen-diner rear extension in Solihull
- Kitchen-diner rear extension in Shirley
- Kitchen-diner rear extension in Acocks Green
- Kitchen-diner rear extension in Chelmsley Wood
- Kitchen-diner rear extension in Kenilworth
Other work in Knowle:
FAQ
Kitchen-diner rear extension questions in Knowle
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.
Is the site visit in Knowle free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you fit the kitchen?
Yes, whether you buy it yourself or we supply it. We take the measurements from the built shell, not the drawings.
How long does a rear extension take to build in Knowle?
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 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.
How much does a kitchen-diner rear extension cost in Knowle?
As a guide, £1,900–£3,100 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £23,000–£37,000 at that rate. Your written price follows the survey.