UK car parks could ‘collapse’ under the weight of EVs, report warns

In recent years, vehicles have become increasingly heavy, with their average weight rising from 1.5 tonnes in 1974 to almost 2 tonnes today. As a result, old multi-storey car parks might be at risk of collapse.

This increase in weight could prove fatal, and might have caused the death of one person in the collapse of a multi-storey car park in New York City in April 2023. The incident is still under investigation. 

To prevent the situation from causing further harm, IStructE commissioned a team of 10 engineers to update design recommendations for multi-storey car parks.

The review's conclusions proposed that car park owners have their buildings inspected by engineering firms to see if they need to be strengthened. If this was not possible, the experts recommended that owners impose a vehicle weight limit of up to two-and-a-half tonnes on old buildings, to lower the risk of collapse. 

“Potentially if we just ignore this issue then we could have a partial collapse," said Chris Whapples, an IStructE fellow. "It would not necessarily be a wholesale collapse.

“I’m not trying to create any scaremongering, and I want to emphasise that not all 6,000 multi-storey car parks across the UK have to be closed. It’s only the very old ones, built in the 60s and 70s, which are in a very poor state of repair and have weakened over time, which will probably need to have some work done to them."

Whapples stressed that the risk of collapse was not caused by small city electric cars but by top-end vehicles such as SUVs which are about three tonnes or over and could potentially be overloading some of these older multi-storey car parks. 

“I can’t say much about the price, because the numbers would be subject to conjecture, and any strengthening procedures would have a price set against them bespoke to each car park," he added.

“I think a lot of old owners will opt for imposing a weight limit rather than paying for strengthening measures.”

The report also highlights that a number of serious fires have happened in car parks which were designed to current guidance, and that in certain circumstances, this may not produce a fire-safe design. 

Structural engineer Mark Punsdack, who was chair of the contributor group, added: “As we move to using more electric or hybrid cars, we are now exposed to risks from vehicle compositions and propulsion systems which current design guidance does not acknowledge. We have moral and legal duties to make buildings accessible for all – and car parks are no exception.” 

Other aspects of car park design considered in the new document include accessibility – there are more motorists with personal mobility issues than in the past – and physical measures that can be part of the building to deter suicide attempts.

“The car parks built today or those being renovated and re-used need to be designed with all this in mind if these structures are to remain viable and useful in a rapidly changing world,” Mark Pundsack said.

The concerns regarding the infrastructure changes needed to make the transition to EVs have been accelerated with the announcement that the UK would impose a ban on the sales of new diesel and petrol cars by 2030.

In February, the European Parliament formally approved a law to effectively ban new sales of carbon-emitting petrol and diesel cars by 2035.