Notwithstanding RSA 153:5, 153:10-b, or any law to the contrary, the fire code applicable to single family dwellings, as defined in RSA 153:1, X, or, where applicable, single rental units in multi-unit dwellings, as defined in RSA 153:1, IX-a and VI, respectively, shall be the fire code applied by the state fire marshal and local fire departments to community living facilities housing 3 or fewer clients.