(a) A total change in the use or occupancy of an existing building which would cause a greater hazard to the public shall not be made unless such building is made to comply with the requirements of the applicable state and local rules, regulations, codes, and standards for the new use or occupancy; provided, however, that the compliance alternative provisions of this article may be utilized by authorized enforcement authorities where total or strict compliance with applicable state or local rules, regulations, codes, or standards is not practical.
(b) When the proposed use is of equal or lesser hazard as determined by an authorized enforcement authority, further compliance with any code for new construction is not required unless otherwise provided in this article. Alterations or repairs to an existing building or structure which do not adversely affect the performance of the building may be made with like materials. Any proposed change to the existing building or change in type of contents of the existing building shall not increase the fire hazard to adjacent buildings or structures. If the fire hazard to adjacent buildings or structures is increased, then requirements of applicable construction or fire safety codes for exterior walls shall apply.