(a) As used in this section, “remodeling” means to substantially improve, alter, extend or otherwise change the structure of a building or change the location of exits, but shall not include maintenance, redecoration, reroofing or alteration of mechanical or electrical systems.
(b) If more than 50% of the interior square footage of a public building is to undergo proposed remodeling, the entire building shall be made to conform to the provisions, including regulations, of section 323 of this title, notwithstanding the date upon which construction of said building was initially completed and notwithstanding any other provision of this chapter or regulations promulgated pursuant thereto.
(c) If between 25% and 50% of the interior square footage of a public building is to undergo proposed remodeling, that part of the building which is to be remodeled shall conform to the provisions, including regulations, of section 323 of this title, notwithstanding the date of completion of the initial construction of said building and notwithstanding any other provision of this chapter or regulations issued pursuant thereto.
(d) If less than 25% of the interior square footage of a public building is to undergo proposed remodeling, the remodeling is not subject to the provisions, including regulations, of section 323 of this title unless the alteration involves work on doors, entrances, exits or public toilet rooms, in which case such doors, entrances, exits or public toilet rooms shall be made to conform to said provisions and regulations, notwithstanding the date of completion of the initial construction of said building and notwithstanding any other provision of this chapter or regulations issued pursuant thereto.
(e) If remodeling is undertaken pursuant to a plan whereby the project is done in stages which, taken together, total one of the applicable interior square footage percentages specified in this section, the appropriate subsection shall be complied with in undertaking the remodeling effort.
(f) In the case of remodeling in a building having mechanical vertical transportation with adequate elevator openings to meet disabled requirements:
(1) If the building has 3 floors or less, accessible toilet room accommodations for each sex shall be provided for the disabled on at least one floor.
(2) If the building has more than 3 floors, accessible toilet room accommodations for each sex shall be provided for the disabled on at least two floors.
(g) The owner of any public building who fails to comply with this section may be compelled to meet its requirements in a court suit by any interested person. Such person shall be reimbursed, if successful, for all costs and disbursements plus such actual attorney fees as may be allowed by the court.
(h) Each toilet room accommodation provided for disabled persons as required under this section shall be identified on its entrance as a disabled accommodation, and directions to such accommodations shall appear at the building's primary entrance.