Estimating your self build costs is fundamental to your project planning.

Let’s have a look at the factors that affect self build costs and how to work out how much yours might be.

Self Build Costs


Calculating a ball-park figure allows you to:

  • Decide if it is economically viable to build your own home.
  • Work backwards to calculate how much you can afford to spend on a plot of land.
  • Assess your borrowing needs.
  • Get an idea of the house you can build within your budget.

Factors Affecting Self Build Costs

The cost of building a house is affected by many factors including:

Build Method

Most build cost calculators work on traditional masonry or timber frame build costs. If you are interested in a specialist build method you should contact specialist companies for estimates. Have a look at the house construction methods options that are available to you.

Geographical Location

Variations in material, labour and equipment prices affect the total build cost. As you’d expect, London is the most expensive area, followed by the South East. The Midlands, Yorkshire, Wales and the North East are the cheapest.

Build Route

The more you do, the more you save. Employing a package company increases the price but reduces the stress. Visit our build route page to look at the options.


Economies of scale apply. Pound per square metre build costs reduce as the size of the property increases. Each additional floor becomes more cost effective than the last.

Materials and Design

Your choice of materials and bespoke design items will have a considerable influence on the cost of building a house.

Build Quality

Better quality = more expensive.

Site Conditions

Contaminated ground, a steep slope or a location in the back of beyond can all wreak havoc with your budget. The actual impact on your build costs are often difficult to predict.

Garages and Outbuildings

Garages and outbuildings must be accounted for. It is usually recommended to budget the same £/m2 for garages as for the main house.

The Building Costs

Build costs are referred to in Pounds per square metre (£/m2) with m2 being the total internal floor area of your proposed home.

Depending on the influence of the factors mentioned above, a traditional masonry or timber frame build in the UK can range anywhere from £600/m2 to £1800/m2.

This variance is by no means restrictive and a cutting edge design and build could come in well above the top figure. If you are considering this, speak to your architect or designer about cost implications.

Build Costs Calculators

To achieve an accurate estimate, have a look at Homebuilding and Renovating (H and R) Magazine’s build cost calculator. It is found near the back pages of their magazine and is an excellent tool. Their figures are regularly updated in line with the Build Cost Information Service (BCIS) of the Royal Institute of Chartered Surveyors (RICS) who provide the industry standard in estimating rebuild costs for insurance purposes.

H and R’s calculator generates an initial figure based on floor area, build route, standard of finish and area of the country. It then takes you step-by-step through adjustments for factors such as slope of site and use of basement or roof space. The result is a pretty good build cost estimate that reflects your plans.

There are some simple and free calculators available online including Buildstore’s – Build Costs Calculator which can quickly give you a rough idea of overall costs.

Other Costs to Remember

People often like to add up the actual build costs and selectively pretend that some others don’t exist. This is bad practice, always budget for everything and remember to include:

  • Land purchase – Solicitor’s fees, stamp duty, other costs.
  • Professional fees – Architects, Planning Consultants, Engineers, etc.
  • Borrowing costs – Interest payments and set up costs. Click for more on mortgages.

The significance of these costs will be specific to your individual project. If they are relevant, then the cost implications should be noted.

The Next Step

By estimating your self build costs you can assess the feasibility of building, set a budget for your plot or begin the design process in earnest. As you move forward you’ll need an accurate set of projected costs which can be used to assist with the design and project management of your build. Our money matters section looks at all things financial in more detail including building up your cost projections.

All this talk of self build costs is a bit draining! It is good to remember though, that by doing it yourself you could save up to 25% of the value of the completed property.

Pop back to the Introduction page for more things to consider.

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