Final answer:
Usable square footage refers to the area that can be used for the tenant's designated purpose, excluding common building areas, while net square footage includes the usable space plus shared spaces for the tenant but not areas used exclusively by building personnel.
Step-by-step explanation:
In real estate, usable square footage refers to the actual area that can be used for the designated purpose of the space, typically within a commercial property. This includes offices, cubicles, and meeting rooms, but excludes common areas, stairways, elevators, and mechanical rooms. On the other hand, net square footage is a broader term that includes the usable square footage plus certain shared spaces that serve the tenant's space, such as restrooms, lobbies, and corridors that are within the tenant's leased area. However, this does not include areas such as mechanical rooms, stairways, and elevator shafts that are used by building personnel and not the tenant directly.