Except as provided in §B of this regulation, the Standards shall apply to all swimming pools and spas for which an application for a building permit is received by a local jurisdiction on or after December 31, 2023. The Standards adopted under this chapter do not apply to a swimming pool or spa built and in operation before December 31, 2023, unless there is an alteration or repair that results in a substantial and material structural change to the swimming pool or spa that occurs on or after December 31, 2023. If there is an alteration or repair to a swimming pool or spa built and in operation before December 31, 2023, that results in a substantial or material structural change, the alteration or repair shall conform to the Standards.