Cost guides · 5 min read
How much does a kitchen extension cost?
An open-plan kitchen diner is the most requested project we do, and for good reason: it transforms how a house lives. But the price is really three things added together, so here is how to budget properly.
The three cost buckets
- The extension shell: the build itself, typically £2,500 to £3,000 per square metre.
- The glazing: bi-folds, sliders and roof lanterns add cost quickly.
- The kitchen: units, worktops and appliances, usually from £11,000 upwards.
A realistic all-in budget
| Project | Indicative all-in (2026) |
|---|---|
| Small rear kitchen extension (~15 m²) + kitchen | £55,000 to £80,000 |
| Medium open-plan kitchen diner (~25 m²) + kitchen | £80,000 to £120,000 |
| Large wrap-around + high-end kitchen | £120,000+ |
Getting it right
Because we design and build, the extension and the kitchen fit are one coordinated job rather than two teams working around each other, which is what keeps a kitchen extension on time and on budget. Our instant estimator gives you an itemised figure in about a minute.
Frequently asked questions
Do I need planning permission for a kitchen extension?+
Many single storey rear kitchen extensions are permitted development, but limits and conservation areas apply. We check and handle the application.
How long does a kitchen extension take?+
Usually around 12 to 18 weeks on site including the kitchen fit, depending on size and glazing lead times.
Should I use one company for the build and the kitchen?+
It is usually smoother and often cheaper, because there is no gap between the builder finishing and the kitchen fitter starting, and one team is accountable for the result.