How is square footage defined in State leases?

DAS uses a net usable square feet calculation to determine square footage for leased space. Net usable square feet is defined as the following: The interior floor area of a building, used for office and other purposes, within the area leased by a tenant which is for its exclusive use: any space shared in common with other tenants, such as entrance and elevator lobbies; hallways, bathrooms, or used by management for other tenants, such as janitorial or electronic/mechanical closets, is not part of net usable area: if these areas are for the sole use of a tenant, they may be counted in that tenant’s net usable area. The measurement includes structural elements of the building found in the tenant’s space, such as columns and projections necessary to the building. Still, it excludes vertical space penetrations of the building, such as elevators, stairwells, air shafts, and stacks. Measurement of net usable space is to the dominant (over 50%) inside face, such as window glass of the exterior wall; to the midpoint of a wall separating a tenant from an adjacent tenant; and to the inside face of a common corridor, elevator shaft, stairway or similar space.