N.H. Rev. Stat. § 47:22
The board of mayor and aldermen, or the corresponding governmental body of any city, is hereby empowered and authorized in the passing and adopting of ordinances, establishing codes, rules and regulations for the construction of buildings, relating to the installation of plumbing, the use of concrete, masonry, metal, iron and wood, and other building material, the installation of electric wiring, and fire protection incident thereto or for the prevention of fires to adopt any additional regulations or amendments provided that such additional amendments are not inconsistent with or less stringent than, nor intended to replace, the requirements of the most recent edition of the state building code adopted under RSA 155-A, or the state fire code adopted under RSA 153, and provided that each amendment submitted to the building code review board or the state fire marshal relates to one article or section of the code. The board of mayor and aldermen may adopt a nationally recognized code not included in, and not inconsistent with, the state building code or state fire code, except for a nationally recognized code which has the same or similar scope or purpose, as determined by the building code review board for amendments to the state building code or the state fire marshal for amendments to the state fire code, that is included in the most recent edition of the state building code adopted under RSA 155-A, or the state fire code adopted under RSA 153, and the intent of this restriction shall not be avoided by the adoption of local amendments as determined by the building code review board for amendments to the state building code and the state fire marshal for amendments to the state fire code. Upon adoption of such ordinance wherein such code, rules and regulations or portions thereof have been incorporated by reference, there shall be filed 3 copies of such codes, rules and regulations in the main office of the municipal department or agency administering the same and 3 copies in the office of the city clerk. All copies of any code, rules and regulations filed as provided herein, shall be for use and examination by the public. Local amendments to the state building code and codes regulated by this paragraph adopted prior to July 1, 2024, and the procedural history of adoption per RSA 155-A:10 shall be submitted for review to the building code review board for review and confirmation that such additional amendments are not inconsistent with or less stringent than, nor intended to replace, the requirements of the most recent edition of the state building code adopted under RSA 155-A. No local amendment shall be enforced if it has not been submitted to the state building code review board within 60 days of the effective date of this paragraph. Upon the withholding of confirmation of a submitted local amendment by the building code review board, the local amendment shall not be enforced. Local amendments to the state fire code adopted prior to July 1, 2024, and the procedural history of adoption per RSA 153:4-a, shall be submitted to the state fire marshal for review and confirmation that such amendments are not in conflict or less restrictive than the state fire code and are based on sound engineering practices. The state fire marshal shall confirm that the local amendments are enacted and adopted by the local legislative body. No local amendment shall be enforced if it has not been submitted to the state fire marshal within 60 days of the effective date of this paragraph. Upon the withholding of confirmation of a submitted local amendment by the state fire marshal local amendment shall not be enforced.
RSA 47:22
1945, 105:1, par. 18. RSA 47:22. 1963, 232:1. 1965, 255:1. 2002, 8 : 2 , eff. Sept. 14, 2002.