Costs to Build Self Storage. To give you even ballpark costs, we will need to know if you are planning to build a single story or a multi-story facility. Costs for Single Story Self Storage Construction typically ranges between $25-$40 per square foot – not including land or site improvement costs.Multi-Story Self Storage Building Costs have more variables and can range from $42 per square foot to as much as $70 per square foot.Today, there are almost unlimited options in designing a self-storage facility that will blend into the area you plan to build.he most common state of the art facility will be about 60,000 - 80,000 net rentable square feet, cost $45-65 per square foot to construct (outside of existing land costs), and have break even operating expenses in the 40-60 percent range (not including debt service) of total stabilized income.