Self-storage UK self-storage space doubled in 10 years to >44m sqft in 2017.  That’s 0.7 sqft for each person, the highest in Europe.  USA self-storage is 7 sqft per person, despite its homes being the world’s largest.  UK: 1,160 indoor & 345 outdoor sites, 450k customers, £750m ($930m) annual sales. We over-estimate the space we…