Notwithstanding sections 28-101.4.3 and 28-102.4.3 or any other provision of this code that would authorize alterations of prior code buildings in accordance with the 1968 building code or prior codes, where the proposed work at the completion of construction will increase the amount of floor surface area of a prior code building by more than 110%, over the amount of existing floor surface area, such entire building shall be made to comply with the provisions of this code as if it were a new building hereafter erected. See section 28-105.2 for permits for such work.
Exceptions. When determining the amount of existing floor surface area for the purposes of section 28-101.4.5, the following shall be excluded from the measured square footage of floor surface area:
1. The square footage of floors removed during the course of the work when such floors are removed together with the supporting beams, joists, decking and slabs on grade.
2. The square footage of any floor that was installed together with the supporting beams, joists, decking and slabs on grade less than 12 months prior to submission of the application for construction document approval for the proposed work. For the purposes of this exception, floors installed pursuant to a work permit signed off less than 12 months before such submission shall not be counted as existing floor surface area.