Area, Gross Floor : The floor area within the inside perimeter of the outside walls of the building under consideration with no deduction for hallways, stairs, closets, thickness of interior walls, columns, or other features
NFPA 101B Code for Means of Egress for Buildings and Structures, 2002 ed. https://law.resource.org/pub/us/code/ibr/nfpa.101. 2003.pdf, (Code: Means of Egress for Build and Struc - Amer) {246 NFC}