The County Commissioners of St. Mary's County are hereby authorized to adopt and to amend from time to time a building code to provide for the construction, maintenance and repair of any and all buildings and structures, located or to be located in St. Mary's County, to provide for the appointment of inspectors for the enforcement thereof, and to provide penalties for the violation of said building code. Said building code may incorporate by reference any code or part thereof proposed by any governmental agency or by the Building Officials Conference of America, Inc., or any other trade or professional association for general distribution in printed form as a standard model on any subject relating to construction, maintaining or repairing buildings or other structures, provided that subsequent amendments to any such model or standard code, shall not be effective until specifically incorporated into such building code.