What is a kitchen extension?
A kitchen extension is an extension designed around a new kitchen, usually an open-plan kitchen, dining and family space at the back of the house. We build the extension and fit the kitchen as one project, so plumbing, electrics and lighting are planned around the layout from the start.
How much does a kitchen extension cost in Orpington?
In Orpington, a kitchen extension typically costs £2,900–£4,400 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £64,000–£97,000. Building costs in London run about 30% above the UK average, and the figures for Orpington are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £43,500–£66,000 |
| Typical project (22 m²) | £64,000–£97,000 |
| Larger project (31 m²) | £90,000–£136,500 |
| Rate per m² | £2,900–£4,400 |
The biggest cost drivers are:
- Underfloor heating and flooring
- Who supplies the kitchen
- Glazing and roof lanterns
- Kitchen units, worktops and appliances
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a kitchen extension in Orpington?
Whether you need planning permission depends on your house and its location in England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
Handled as part of most kitchen extensions:
- Building control sign-off
- Drainage and water supply positioned for the sink and appliances
- Flooring and decoration
- Extraction ducted to outside
- Kitchen layout planned alongside the extension design
- Electrics, lighting plan and sockets
How long does it take?
Expect 11 to 16 weeks on site, including kitchen fitting. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.
Building in Orpington
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
Our Orpington coverage includes postcode districts BR6, and we also work in nearby places such as Sidcup, Swanley and Bromley.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about kitchen extensions in Orpington
Will I need planning permission?
The same rules apply as for any extension. Many single-storey kitchen extensions are permitted development; larger or wraparound designs need an application.
Should the kitchen be designed before the extension?
Yes. Knowing where the sink, hob and island will go lets us place drains, ducting, sockets and windows correctly during the build.
Can I buy my own kitchen?
Yes. You can supply it and we fit it, or we supply it as part of the price. Either way we coordinate deliveries with the build programme.
How long does a kitchen extension take in Orpington?
Typically 11 to 16 weeks on site, including kitchen fitting. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a kitchen extension cost in Orpington?
In Orpington, a kitchen extension typically costs £2,900–£4,400 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £64,000–£97,000. Your fixed price depends on the survey and drawings.