As the old saying goes, you never know what happens behind closed doors. And, but for the odd glimpse, Robin Greenwood, chief executive of Storage King, has little idea what the hundreds of units at the company’s 26 sites contain.

With the emphasis on customers’ privacy – Storage King staff are only authorised to enter stores in an emergency – Greenwood and his employees base what is put into the units on trust and a legal agreement that there will not be “anything illegal like drugs, firearms, fireworks, or livestock. I haven’t yet seen anyone try to store a sheep,” Greenwood quips.

What he has glimpsed through Storage King’s blue doors varies from train sets to extravagant drag queen costumes: items private customers – who make-up 65% of Storage King’s clientele –either don’t want to keep at home or haven’t got room for.