Typical 2026 prices for single storey, two storey and kitchen extensions, with worked examples and the fees to budget for.
A single storey extension in the UK typically costs £1,800 to £3,000 per square metre to build in 2026, before VAT and professional fees. London and the South East sit at the top of that range or above it. The Midlands usually sits lower.
That means a typical 3 by 6 metre kitchen extension, 18 square metres, costs roughly £32,000 to £54,000 to build, before the kitchen itself, VAT and fees. These are guide figures from industry sources, not a quote. For a figure based on your house, try our cost calculator or book a free survey.
About £1,800 to £3,000 per square metre. A 3 by 6 metre extension is roughly £32,000 to £54,000 before VAT, fees and the kitchen.
Usually less per square metre than single storey, because the foundations and roof serve two floors. A 3 by 6 metre two storey extension adds 36 square metres and often lands around £60,000 to £95,000.
Smaller in area but often more complex, with steels and party walls. Typically £35,000 to £60,000 including the opening into the existing kitchen.
Side and rear together. Usually £70,000 upwards, depending on size and glazing.
A budget kitchen of six units, a sink and a basic worktop can be around £2,500. Most people end up nearer £8,000 to £15,000 once they choose the units, worktops and appliances they actually want. We price budget, mid and high spec separately so you can see the difference.
Professional fees. Drawings, structural calculations and building control together often add 10 to 20 percent to the build cost. A structural engineer usually charges £600 to £1,800 and building control roughly £850 to £1,350 for an extension.
Planning. Many single storey extensions are permitted development and need no application. A householder planning application currently costs a little over £500 in England, and a Lawful Development Certificate costs half that. Check the Planning Portal for the latest fees.
Party wall. If you build on or near a shared boundary, your neighbours must be served notice. If surveyors are appointed, budget £1,000 to £2,500 per neighbour.
Finishes and fittings. Glazing, flooring, lighting and the kitchen can move the total more than the build itself. Bifold or sliding doors alone range from a few thousand pounds to well over £10,000.
VAT and contingency. Check whether quotes include VAT at 20 percent, and hold back 10 to 15 percent for anything found in the ground.
Often it is cheaper to extend. Moving costs stamp duty, agent and legal fees, removals and usually a higher mortgage. An extension adds space and often value to the house you already own.
The total is higher, but the cost per square metre is usually lower because the foundations and roof cover twice the floor space. If you might want upstairs space later, building both now is usually better value.
A single storey extension is usually 8 to 16 weeks on site and a two storey 12 to 22 weeks, plus time beforehand for drawings and approvals.
Keep the shape simple, use standard window and door sizes, avoid moving drains where you can, and choose a mid range kitchen. A clear, itemised quote helps you see where the money goes.
No. We never take money up front. You pay in stages as the work is done.
Tell us what you have in mind and we will book a free visit. Your itemised quote comes back within 3 to 5 working days.