Insert a new Section 704.2 into the Existing Building Code to read as follows:
Allowance for Fire Resistance Upgrading. When improving the fire resistance rating of the enclosure of stairways, exit access corridors or exit passageways complying with Section 1005 of the Building Code, a tolerance of up to 1-1/2 inches (38 mm) shall be allowed in the minimum width of those elements of egress. When improving the fire resistance rating of a wall assembly on one side of stairways, exit access corridors or exit passageways, a tolerance of up to 3/4 inches (19 mm) shall be allowed in the minimum width of those elements of egress
D.C. Mun. Regs. tit. 12, r. 12-J704