The business has acquired 15 self storage facilities in Kent, Brighton & Hove, East Sussex, West Sussex, Norfolk, Suffolk, Essex, Buckinghamshire, Hertfordshire and Surrey.
The deal I with operator Big Box is valued at more than £100m and gives the firm 674,760 sq ft of new UK floorspace.
StorageMart, controlled by the Burnam family, already has 174 locations in the US and Canada.
The StorageMart brand is the world’s largest privately-owned self storage provider, with over 12.5m sq ft of storage.