Kitchen Extension Cost Guide 2026
A kitchen extension is two budgets in one: the extension (structure) and the kitchen (units, worktops, appliances). The most common mistake is underestimating the kitchen budget. This guide breaks down both.
Cost breakdown
Extension build cost
The extension structure (foundations, walls, roof, windows) costs £1,800–£2,800 per m². A typical kitchen extension of 20–30m² costs £36,000–£84,000 for the build alone.
Kitchen fit-out cost
Budget kitchens start at £5,000–£8,000. Mid-range (Howdens, Wren, Magnet) costs £8,000–£18,000. Premium (Roundhouse, deVOL, Smallbone) runs £20,000–£50,000+. Appliances add £2,000–£8,000. We recommend allocating 20–30% of the total project budget to the kitchen.
| Component | Budget | Mid-Range | Premium |
|---|---|---|---|
| Extension (24m²) | £43,000 | £55,000 | £67,000 |
| Kitchen units | £5,000 | £12,000 | £30,000 |
| Appliances | £2,000 | £5,000 | £8,000 |
| Bi-fold/sliding doors | £3,000 | £5,000 | £8,000 |
| Underfloor heating | — | £2,500 | £4,000 |
| Professional fees | £2,000 | £3,500 | £5,000 |
| Contingency (15%) | £8,000 | £12,000 | £18,000 |
| **Total** | **£63,000** | **£95,000** | **£140,000** |
Prices based on Dorset rates, 2026
Frequently asked questions
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