National Storage Affiliates Trust Trust is a real estate investment trust. The company owns, operates, and acquires self-storage properties located within the metropolitan statistical areas throughout the United States. It owned a diversified portfolio of more than 1050 self-storage properties, located in more than 42 states and Puerto Rico, comprising approximately 67.8 million rentable square feet, configured in approximately 533,000 storage units. National Storage's portfolio consists of self-storage properties designed to offer convenient, affordable, and secure storage units.