How to set a budget for building your own house

If you're a Grand Designs fan, chances are you've day dreamed about a self build project at least one time.

By Hugh Metcalf | 17 February 2020

Want to know how much it costs to build a house in the UK? We get the experts to explain how to work out how much you can, and should, spend on a self build.

baufritz budget s1 build house in germany - grand designs

Image: Not only is this S1 type kit house from Baufritz affordable to erect, it features smart energy efficiency technology that contirbutes to low running costs. 

If you’re a Grand Designs fan, chances are you’ve day dreamed about a self build project at least one time. It can sometimes feel a bit of a mystery as to whether a self build is within your reach or, when it does come to building your own house, how much you should budget for the build.

The truth is, self-building can be a way to really make the most of your money and create a home that you may not otherwise be able to afford.

We asked the experts for what you need to know in setting a build budget, and how best to stick to it.

Use average property prices as a guide

entarnce to modern self build home built into a clifftop featured on grand designs

Image: The owners of this clifftop house, featured on Grands Designs in 2019, bought the land for £120,000, and spent £420,000 on the build. The resulting property has a market value of £650,000. 

Data scientist Anna Powell Smith explains how to set a budget that will reflect the value of your completed project:

“Use average property prices per square metre in the area you are concerned with when deciding what budget to set for a renovation or self-build. Speak to local estate agents, builders or architects to get an idea of the local per square metre property values, or use online services that list average house prices per square metre.”

Your budget should be, at maximum, equal to the average property price per square metre multiplied by the square meterage of your propsective build, minus the price of the land to avoid the build entering negative equity.

The actual cost of the work is something that will depend on a whole range of factors. Consider using the square meterage information in tandem with a self build cost calculator to get an idea of how far your budget will go.

We’re well-versed with overspending Grand Designers by now, so building in a contingency of 10-20% is important. Having this built in from the outset will help to prevent going way  over budget.