SECTION 1. Section 26A ½ of Chapter 148 of the General Laws as appearing in the 2018 Official Edition is hereby amended by deleting the following phrase from the first paragraph of said Section 26A ½: “provided, further, that sprinklers shall not be required to be installed in buildings where construction has commenced prior to January first, nineteen hundred and seventy-five and which have been submitted to the provisions of chapter one hundred and eighty-three A;” and replacing it with the following: ”any building where construction has commenced prior to January first, nineteen hundred and seventy-five and which have been submitted to the provisions of chapter one hundred and eighty-three A shall comply with the following schedule for the installation of automatic sprinklers: - one-third of the gross square footage of the building or structure shall be equipped with automatic sprinklers by March thirtieth, two thousand and twenty- four; two-thirds of the gross square footage of the building or structure shall be equipped with automatic sprinklers by March thirtieth, two thousand and twenty- seven; and the entire gross square footage of the building or structure shall be equipped with automatic sprinklers by March thirtieth, two thousand and thirty-one; provided, however, that the owner of said building or structure may apply to the board of appeals of the fire safety commission for an extension or a waiver of the provisions of this section as provided for in section two hundred and one of chapter six. Any building or structure subject to the provisions of this section shall have the option of complying with the following schedule: the entire gross square footage of the building or structure shall be equipped with automatic sprinklers by March thirtieth, two thousand and twenty-seven; provided, however, that under said option the owner of said building or structure shall be deemed to have waived his right to any such extension of time.”