Despite the best of intentions, 60% of self build projects go over budget according to a report produced and commissioned by Homebuilding & Renovating.

The report, based on a survey of 500 self builders, explains that while these projects typically went over by 20%, in some cases going over budget lead to greater profitability when it came to expected market value.


It is also crucial to understand the context around the overspend. More than half of those who had overspent, did so because they decided to build bigger or up the specification during the process, while more than a third who ran over budget were hit by unexpected extras.

But while going over budget is a stressful time, the majority of those who overspent made a better profit when it came to market value estimates for their finished home.

Who Overspends?

According to the survey results, it tends to be younger self builders who go over budget – which could be attributed to their financial flexibility and greater ability to borrow. Older self builders who are more reliant on their accrued housing equity may have a more constrained final budget.


One in five were motivated by financial benefits, but other factors including location, available land and build quality were all motivations as to why these projects went over budget.

Interestingly, the impact of overspending on profit does vary depending on the motivation behind it. Those busting the budget for financial benefit were half as likely to make a loss financially on their build as their peers, while those overspending for build quality reasons seem four times more likely to make a loss.

However, it can be argued that those who focus on build quality are those who are expecting to live in the property long term and may reap those costs back through reduced maintenance and repairs, thereby making the initial overspend a good investment.

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