How Much Does a Kitchen Extension Cost in London? (2026 Guide)

If you are planning a kitchen extension in London, the first question you will ask is: how much is this going to cost? The honest answer is that it depends — but armed with the right information, you can plan with confidence and avoid nasty surprises.

At NGC Build, we have been transforming London homes with bespoke kitchen extensions for years. This guide gives you a straight-talking breakdown of what a kitchen extension costs in London in 2026, what drives the price up or down, and what to watch out for.

Average Kitchen Extension Cost in London (2026)

In 2026, a kitchen extension in London typically costs between £2,500 and £4,500 per square metre, depending on the specification, materials, and complexity of the project. Here is a realistic overview of total project budgets:

• Build only (no kitchen fit-out): £45,000 – £85,000

• With mid-range kitchen included: £70,000 – £120,000

• High-end kitchen fit-out: £110,000 – £180,000

These figures reflect quality construction in London — not budget shortcuts. The size of your extension and the level of finish you choose will have the biggest impact on the final figure.

What Affects the Cost of a Kitchen Extension?

1. Size of the Extension

The larger the extension, the more it costs — but the cost per square metre often reduces slightly as the project grows. A 20m² extension in London could cost between £50,000 and £90,000, while a 40m² project might run from £100,000 to £180,000.

2. Design Complexity

Simple rectangular extensions with standard materials sit at the lower end of the scale. Add bifold doors, a glazed roof, structural steel, or underfloor heating and costs will rise accordingly — but so will the quality and light in your new space.

3. Kitchen Specification

A mid-range fitted kitchen from a reputable brand will cost somewhere between £15,000 and £30,000, fitted. A bespoke, high-end kitchen can run from £40,000 upwards. Appliances, worktops, and cabinetry all add to this figure.

4. Structural Work

If your extension requires removal of a load-bearing wall, or if ground conditions require additional foundations, these structural elements will add cost. A steel RSJ beam, for example, typically costs £1,500 – £4,000 fitted.

5. Planning and Building Regulations

Many single-storey kitchen extensions in London fall under permitted development rights, meaning no formal planning application is needed. However, larger or more complex projects will require planning permission. Budget for the following:

• Planning drawings: £1,200 – £3,000

• Planning application fee: £548 (as of April 2026)

• Building control: £700 – £1,500

• Structural engineer: £800 – £2,500

Hidden Costs to Budget For

Even with a detailed quote, some costs catch homeowners off guard. Here are the most common ones to factor into your budget from the start:

• Party wall agreement (if you share a wall with a neighbour): £700 – £2,000

• Drain surveys and any drain relocation required

• Temporary kitchen facilities during the build

• Decoration and finishing works after handover

• New furniture and soft furnishings for your extended space

We always recommend setting aside a contingency of 10–15% on top of your quoted build cost. This gives you breathing room if anything unexpected arises during construction.

Does a Kitchen Extension Add Value to a London Home?

Almost always, yes. A well-designed kitchen extension is one of the highest-return home improvements you can make in London. It can add between 10% and 25% to the value of your property, and it dramatically improves how you live in your home day to day.

When you consider that moving to a larger home in London involves stamp duty, legal fees, and agent costs that can easily reach £40,000 – £80,000 before you have even unpacked — extending often makes much better financial sense.

Is It Worth Extending Rather Than Moving?

For most London homeowners, the answer is yes. Extending lets you stay in the neighbourhood you love, in the home you have already made your own — while gaining the space and kitchen you have always wanted. The cost of extending is almost always lower than the total cost of moving to a comparable larger property in the same area.

Why Choose NGC Build for Your Kitchen Extension?

At NGC Build, we offer a full design and build service for kitchen extensions across London. From initial concept through to final handover, our team manages every stage of your project — architecture and planning, structural engineering, construction, and fit-out.

We believe every London home deserves a kitchen extension that is built to last, designed with care, and delivered without the stress. If you would like to discuss your project and get a detailed, transparent quote, get in touch with our team today.

• Full design and build service across London

• Transparent, itemised pricing — no hidden costs

• Experienced team with a proven portfolio of London projects

• End-to-end project management from planning to handover