British lifts are no longer big enough to fit the average adult, with engineering experts warning that passenger capacity signs have become “out of date” as waistlines across the country continue to expand.
The maximum number of people a lift claims it can carry is calculated on the basis of assumptions about weight that have not been updated in more than two decades, according to research presented at the European Congress on Obesity in Istanbul. Manufacturers are legally required to display the maximum number of passengers a lift can accommodate, but those figures now bear little relation to the reality of modern body sizes.
Outdated weight assumptions
In the mid-1970s the average weight of a man in the UK was 75kg and the average weight of a woman was 65kg. Today those figures stand at roughly 86kg for men and 73kg for women. Despite this sustained increase, lift manufacturers have continued to base their passenger capacities on an assumed average weight of 75kg per person — the same figure that was used when many of the country’s lifts were first designed.
Professor Nick Finer, President of the International Prader-Willi Syndrome Organisation, led a study that examined 112 lifts manufactured by 21 different companies between 1970 and 2024 across seven European countries: the UK, France, Germany, Spain, Italy, Austria and Finland. He compared the average weight allowance per person in each lift — calculated by dividing the maximum weight allowance by the maximum number of passengers — with the average adult weight for the year of manufacture, taken from the UK National Health Survey.
The results showed that between 1972 and 2002, lift weight allowances did keep pace with rising population weights. But after 2002 the correlation broke down. There was no significant increase in the assumed average weight of lift users after that point, even though the average adult weight in the UK had climbed to 79kg. Manufacturers, Prof Finer found, still design lifts as though every passenger weighs 75kg.
How manufacturers calculate capacity — and why it is now wrong
The reason for the discrepancy appears to lie in a shift in the way manufacturers calculate lift capacity. Prof Finer suggested that many companies may have moved away from a weight-based calculation altogether and instead estimate capacity based on floor space — how many people can physically stand inside the lift car. This approach does not account for the fact that people today are not only heavier but also larger in body size, meaning the same floor area can hold fewer individuals than it once did.
The historical standardisation of lift design in the UK goes back to the post-war era, when a need for cost efficiency led to a set of widely adopted dimensions. In the late 1960s, Otis produced one of the first standardised lift ranges in Britain, noted at the time for its quality and robustness. Those standards have largely persisted, even as the population has changed.
Modern lifts must comply with a suite of regulations, including the Lifts Regulations 2016 (which implemented an EU directive and was preserved and amended after Brexit), the Supply of Machinery (Safety) Regulations 2008, the Health and Safety at Work Act 1974, and the Provision and Use of Work Equipment Regulations 1998. European standards in the EN 81 series — particularly EN 81-20 on design and construction and EN 81-50 on testing and certification — govern safety and accessibility. But none of these standards require manufacturers to periodically update the passenger weight assumptions used in capacity calculations.
Building regulations in England, including Approved Document M (Accessibility) and Approved Document K (Protection from falling, collision and impact), set out requirements for lifts in new buildings, but again do not mandate a specific weight-per-person assumption.
Safety and dignity at risk
Prof Finer told the congress that the failure of lift manufacturers to adapt to rising levels of obesity and body size means that “lift capacities are overestimated”, leading to “increased journey times and compromised safety”. A lift that is overloaded in real terms but not flagged as such may suffer operational problems such as sudden cut-offs or reduced efficiency.
He added: “What’s more, suggesting more people can fit in a lift than is comfortable is stigmatising people living with obesity.” In the abstract presented to the conference, he concluded that “overall manufacturers were not adjusting the capacity of lifts to reflect secular increases in population average weights”.
The problem is not confined to lifts. Experts have noted that other public infrastructure — including train and plane seats, and even doorways — may also be inadequately sized for a growing population. The issue raises questions about dignity, accessibility and inclusion for everyone, regardless of body size.
Obesity in Britain: the wider picture
According to the NHS, 30 per cent of adults in England were living with obesity in 2024, and 66 per cent were either overweight or obese. The prevalence of overweight (including obesity) has risen from 53 per cent in 1993 to 66 per cent today. Obesity prevalence peaks among adults aged 55 to 74, and rates are significantly higher in the most deprived areas of the country. Estimates suggest that by 2040, more than 70 per cent of UK adults could be classed as obese, with 21 million adults affected.
The economic toll is considerable. Obesity-related ill health reduces workforce productivity and places a heavy burden on the NHS. Estimates put the annual cost of obesity at between 1 and 2 per cent of GDP. In 2019, the cost was estimated at £698 per person in the UK, a figure that is projected to reach £1,691 per person by 2060.
Childhood obesity: a crisis in miniature
The rise in weight is also being seen among children. New NHS England data has revealed that more than 6,000 severely obese children in England have sought help from specialist weight management clinics in just three years, including more than 400 aged under four.
Some of the children referred to the Complications from Excess Weight (CEW) initiative weighed 123kg at the time of referral. Some had a body mass index (BMI) of 42, indicating very severe obesity. Around 17 per cent of these children had developed high blood pressure and 6 per cent had type 2 diabetes, while many also suffered from liver disease and obstructive sleep apnoea.
Professor Simon Kenny, NHS England’s National Clinical Director for Children and Young People, said: “These specialist clinics support children to lose weight safely and build healthier long-term habits through tailored care from expert NHS teams. In some cases, these clinics are helping children who could otherwise face a life cut tragically short, dying decades too soon, to look ahead to a full and healthy life. Childhood obesity remains one of the biggest public health challenges facing the country, and the NHS is committed to stepping in early to help prevent serious long-term health complications.”
In 2023/24, the National Child Measurement Programme found that 9.6 per cent of reception-aged children (4-5 years) in England were obese, rising to 22.1 per cent of Year 6 pupils (10-11 years). Obesity prevalence increases with age, from 10 per cent of those aged 2 to 4, to 17 per cent of those aged 13 to 15. Rates are particularly high in the most deprived areas.
Prof Finer’s research — conducted in his capacity as president of the International Prader-Willi Syndrome Organisation, a rare genetic disorder that causes hyperphagia (excessive appetite) and often leads to severe obesity — highlights a fundamental mismatch between the infrastructure people rely on every day and the bodies they now have. Without an update to the assumptions built into lift design, he warned, both safety and dignity will continue to be compromised.