If you are thinking about building a house, the first question is almost always about money. The honest answer is: it depends. But a starting point helps, so her are some figures to help you get started on a budget.
The headline figures
As a benchmark, the cost to build a house in the UK in 2026 sits somewhere between £1,800 and £3,500 per square metre. A typical three-bedroom detached house of around 120m² will cost roughly £216,000 to £420,000 for the build alone, before you add land, professional fees, and VAT.
That range is wide because so much depends on specification, location, and design. A simple, rectangular home with standard finishes sits at the lower end. A bespoke, architect-designed house with premium fittings and a complex roofline sits at the top.
What drives the price up or down
Specification. This has the biggest single impact on cost per square metre. A basic specification with standard kitchens and bathrooms might come in at £1,800/m². A high specification with bespoke joinery, underfloor heating, and smart home technology can push that to £3,200/m² or more.
Location. Building in London and the South East costs significantly more than in the North or Midlands, largely down to labour rates and site access. The gap between regions can be 25 to 30 per cent.
Design complexity. A simple two-storey rectangular home is the most cost-effective form to build. Every bay window, change in roof level, or curved wall adds labour time and materials. Single-storey homes also cost more per square metre than two-storey ones since the roof and foundations are spread over less floor area.
Construction method. SIPS (structural insulated panels) and ICF (insulated concrete formwork) usually cost around the same per square metre as traditional methods, such as masonry and standard timber frame. SIPS panels are manufactured off-site and erected in days rather than weeks, cutting labour costs and reducing the time the site is exposed to weather. ICF forms are filled with concrete on site, creating walls with high thermal mass and strong sound insulation, though services need to be planned in before the pour. In both cases any extra spent on materials is clawed back through a shorter build programme, less snagging, and lower running costs once you move in.
SIPS and ICF work out better value over the life of the house. Both systems are built to far tighter tolerances than brick-and-block, so the finished shell is more airtight and better insulated from day one, which means lower heating bills for as long as you own the house.
Beyond the build cost
The per-square-metre figure only covers construction. You will also need to budget for:
- Architectural drawings and design fees (typically 8 to 15 per cent of the build cost)
- Structural engineering
- Planning permission (the application fee for a new dwelling in England is £610 per 0.1 hectare of site, for sites under 0.5 hectares)
- Site surveys
- Utility connections
- A contingency fund of at least 10 to 15 per cent for the unexpected
Most experienced builders will tell you the same thing: it’s the unforeseen costs, not the headline build rate, which catch people out. Poor ground conditions, restricted site access, or a change of mind halfway through the project can all add up quickly.
Why a quote based on your actual drawings matters more than any average.
Every figure above is a guide, not a quote. The only reliable way to know what your specific project will cost is to work from proper drawings and a detailed bill of quantities. Two houses of the same size, on paper, can end up costing very different amounts once you factor in ground conditions, finishes, and the realities of the site itself.
This is where working with a team that handles design and build together makes a genuine difference. When the people pricing your project are the same people who will be building it, the figures you are given are grounded in what is achievable, not a rough average pulled from a calculator.
Sources
The figures are correct as of mid-2026. Build cost ranges and regional variation: Doherty Builders and Mixdesigncalc. Contingency guidance: Checkatrade. Planning application fees: Planning Portal, official fee schedule effective 1 April 2026 (note that a further increase was under government consultation at the time of writing, so it’s worth checking the current rate before budgeting).
Getting a realistic figure for your project
If you are planning a new build, extension, or renovation and want a cost picture based on your actual site and ambitions rather than a national average, we would be glad to talk it through. Get in touch with the Marptree team to discuss your project.