The term "floor area", as employed in this chapter, in the case of office, merchandising or service types of use, shall mean the gross floor area of a building or structure used or intended to be used for service to the public as customers, patrons, clients, patients or tenants, including areas occupied by fixtures and equipment used for display or sale of merchandise. "Floor area", for the purposes of this chapter, shall not include any area used for:
A. Storage accessory to the principal use of a building.
B. Incidental repairs.
C. Processing or packaging of merchandise.
D. Show windows or offices incidental to the management or maintenance of a store or building.
E. Restrooms.
F. Utilities.
G. Dressing, fitting or alteration rooms. (1996 Code app. A § 10.2-6.2)