My outlet for moving
Consider not only the area taken up by the objects to be stored, but any extra space you might need. For example, if you plan to pack the unit, leave everything in it for a period of time, then unpack the entire unit and bring all the objects home, you will need only the space taken up by your belongings themselves. However, if you plan to use the unit as long term storage and visit periodically to take out boxes and put new objects in, you will need extra space for aisles. You may even need garage shelving, both to make finding objects easier and to prevent delicate boxes from being crushed in the stacks. Choosing the right amount of climate control is also necessary.