Self Build Mortgages > How much does it cost to build a 4 bed house?

How much does it cost to build a 4 bed house in the UK?

The short answer is it depends. Build costs vary widely depending on specification, location, design, and site conditions. In 2025, you can expect the build cost for a typical four-bedroom home to fall between £260,000 and £480,000, before factoring in land, professional fees, external works, and contingency.

Of course, if you want this to be more grand or impressive, with higher quality finishes, this build cost can increase.

What do we mean by a 4 bed house?

A ‘4 bed house’ can cover lots of possibilities, so for context of this page we are assuming this is:

  • Floor area between 140m² and 200m² (average family home size).

  • Two storeys with four bedrooms, living area, kitchen, bathrooms.

  • Standard construction (brick/block or timber frame).

  • Moderate finishes (not ultra-budget, but not ultra-luxury).

It’s important to note that your choices (like high end finishes, eco-credentials, complex design choices) can significantly move this budget. So this is an indication only. You can get a FREE instant build cost quote to give you a more personalised estimate.

Average UK build costs in 2025

Most UK self builds are priced per square metre. Recent UK data, and our own clients experiences, suggests:

  • Basic spec: £1,750 – £2,000 per m²

  • Standard spec: £2,000 – £2,400 per m²

  • High spec / premium: £2,500 – £3,200+ per m²

So for a 160m² four-bed home:

  • Basic: ~ £280,000 – £320,000

  • Standard: ~ £320,000 – £384,000

  • High spec: ~ £400,000 – £512,000

These figures are build costs only. They don’t include the plot, fees, or extras, which can add 20–40% on top.

What else will you have to budget for?

You’ll need to budget for more than just the build cost. Again, these are dependent on projecr but could include:

✔ Planning and regulation fees

✔ Site works

✔ Utility connections

✔ External works

✔ Internal finishes

✔ Insurance and warranties

✔ Contingency funds

✔ Professional fees

Regional cost differences

  • London & South East

    These are the highest labour and land costs, so we recommend you add 10 to 20% of the average build costs on.

  • Midlands & North

    Typically average or even lower labour rates, so build costs can be closer to the middle range.

  • Scotland & Wales

    You’ll likely see more variation on costs depending on remoteness of the site and supply chain access. So do your research.

  • Rural Sites

    May require you to spend more on access roads, drainage, and general services.

Timber frame up to begin a self build house

Example Self Build cost breakdown

Let’s take an example of a standard four-bed detached house, 160m², in the Midlands.

  • Build cost (rough standard spec estimate): ~£352,000

  • Professional fees: ~£35,000

  • Site preparation & utilities: ~£25,000

  • External works (driveway, garden, garage): ~£20,000

  • Insurance, warranty, planning fees: ~£8,000

  • Contingency (10%): ~£44,000

Total project cost (excluding land): ~£484,000

Costs can seem to rise quickly once everything is included, but breaking it down will help your budget be more realistic.

Benefit of build cost calculators

Cost calculators are a great way to estimate early budgets. Mayflower’s own calculators let you:

  • Input your house size, specification, and location.

  • See how costs adjust based on your choices.

  • Link straight to mortgage affordability tools.

It will then give you an instant estimated build cost quote so you can start planning effectively.

Your 4 bed build cost checklist

Before you get started, we recommend making sure you’ve considered:

✔ Plot purchase and legal checks

✔ Planning permission secured

✔ Costed breakdown

✔ Planning drawings

✔ Builders/ contractors chosen

✔ Insurance and warranty arranged

✔ Contingency fund

✔ Finance lined up (with us!)

Why work with Mayflower Mortgage?

We know that building your own home is a big step. We also know that having the right mortgage partner makes all the difference.

That’s why we are here to help you start, and end, your build with confidence.

  • Give you fast, clear decisions, so you can move forward without delay.

  • Provide a dedicated adviser who guides you from first plans to final stage release.

  • Specialise in self build, renovation, and conversion mortgages. So we are experts.

  • Offer our unique Self Build Saver Solution, designed to save you thousands over the course of your project.

  • Winner badge

    Best Self Build Mortgage Advisory Firm

    Design and Build Awards 2025

  • Finalist badge

    Best Specialist Broker

    Finalist at the 2025 Mortgage Strategy Awards

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    Best Specialist Broker

    Finalist at the 2025 Financial Reporter Awards

  • Gold oval badge for the National Custom & Self Build Association (NACSA) indicating support as a Gold Partner for 2024, with website www.nacsba.org.uk.

    NaCSBA Gold member

    National Custom & Self Build Association

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    Grand Designs

    As seen at Grand Designs Live in London

  • Logo for 'Build It Live' event with the phrases 'Self Build,' 'Home Design,' 'Renovation,' and 'Extension' listed below.

    BuildIt Live

    As seen at BuildIt Live

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    As seen at the Homebuilding & Renovating Show

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    AMI Member

    Association of Mortgage Intermediaries

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    STA

    Structural Timber Association Member

Ready to start your Self-Build?

Every great home begins with a clear plan and the right support. Whether you want an instant estimate of your build costs or expert guidance on finance, we’re here to help.