Homeowners planning bathroom renovations are significantly underestimating how much their projects will cost, according to new research from the Federation of Master Builders (FMB).
The study found that 71% of homeowners expect bathroom renovation to cost under £10,000, despite industry professionals warning that realistic budgets are often considerably higher.
The findings suggest widespread misconceptions about both pricing and project timelines, which may leave homeowners financially exposed.
Article continues belowWidespread misunderstanding of real renovation costs
The research highlights a strong disconnect between expectation and reality when it comes to bathroom budgets. A quarter of homeowners (26%) believe a full bathroom renovation can be completed for under £5,000, while just 3% expect costs to exceed £15,000.
Despite this, builders say those lower figures rarely reflect the reality of labour-intensive work, unexpected structural issues, and quality materials required for long-lasting results. The FMB notes that labour alone is often the largest cost component, yet only 38% of respondents correctly identified it as the most expensive part of a renovation.
Brian Berry, Chief Executive of the Federation of Master Builders, said: “Bathroom renovations are one of the most common home improvement projects, but our research shows homeowners are walking into them with unrealistic expectations about both costs and timelines."
He added: "The gap between what people think they'll pay and what they actually need to budget is setting them up for disappointment - or worse, pushing them towards rogue traders offering unrealistic quotes and timelines.”
Timeline expectations also out of step with reality
Beyond budgeting, the study found that homeowners are also significantly underestimating how long bathroom renovations take.
Nearly one in five (19%) expect a full renovation to be completed in a week or less, while 39% believe it can be finished within two weeks.
Industry professionals argue that this is unrealistic once stripping out, plumbing, electrics, waterproofing, drying times, and multi-trade coordination are taken into account. Rushed schedules, they warn, are often linked to poor-quality finishes and long-term maintenance issues.
David Gutierrez, FMB London President and Director of FMB member companies AMIC Ltd and Nest Building Group, said: “We see this expectation gap every week. Clients come to us thinking a bathroom renovation will cost £6,000 and be done in five days, and we have to walk them through the reality. Quality work takes time – you're coordinating plumbers, electricians, tilers, sometimes structural work. Rushing it is how you end up with leaking showers and cracked tiles six months down the line.”
Risk of rogue traders exploiting unrealistic expectations
The FMB warns that this mismatch between expectations and actual costs can leave homeowners vulnerable to so-called “cowboy builders” who offer artificially low quotes to win work.
Berry added: “When someone thinks a full bathroom can be done for £3,000 in five days, they're prime targets for cowboys who will take a deposit, do substandard work and disappear. Most homeowners are budgeting for the bathroom they imagine, not the bathroom they'll actually get.”
The organisation says the issue is part of a wider consumer protection problem, with the UK construction sector having seen billions lost to rogue traders in recent years.
When low expectations lead to costly mistakes
One homeowner affected by a poorly executed renovation described the lasting impact of choosing the cheapest quote.
“I don't take baths anymore. It's hard to relax when you look around your bathroom and see thousands of pounds you've wasted,” they said. “Our quote came in at under half the price of installers from the retailer we bought materials from and we thought we'd get a bargain. Instead, we were left with uneven tiles, squiggly sealant, damaged fixtures including our toilet, and a radiator that doesn't work.”
The FMB says cases like this underline the importance of realistic budgeting, proper vetting of tradespeople, and recognising that quality bathroom renovations require both time and investment.
