The plumbing board shall have power, and it shall be its duty, to adopt rules and regulations, not inconsistent with the laws of the state or the ordinances of the city or village, for the sanitary construction, alteration, and inspection of plumbing and sewerage connections and drains placed in, or in connection with, any and every building in such city or village, in which it will prescribe the kind and size of materials to be used in such plumbing and the manner in which such work shall be done, which rules and regulations, except such as are adopted for its own convenience only, shall be approved by ordinance by the mayor and council of such city or by the chairperson and board of trustees of such village. The board shall have the power to amend or repeal its rules and regulations, subject, except such as relate to its own convenience only, to the approval of the mayor and council of such city or chairperson and board of trustees of such village. In cities of the metropolitan class the plumbing board shall have the power, without the approval of the mayor and city council, to grant a variance from the ordinances, rules, and regulations in the kind and size of materials to be used or in the manner in which the work is to be performed. The variance shall apply only to a single building and shall not be considered as a part of the ordinances, rules, and regulations of the plumbing board. If there are practical difficulties or unnecessary hardships in the manner of strictly carrying out such ordinance, the plumbing board shall have the power, in passing upon a variance, to vary or modify the application of any of the regulations or provisions of such ordinance relating to the use, construction, or alteration of buildings or structures or the use of land, so that the intent of the ordinance shall be observed, public safety and welfare secured, and substantial justice done. The board shall have power to compel the owner or contractor to first submit the plans and specifications for plumbing that is to be placed in any building or adjoining premises to the board for approval before it shall be installed in such building or premises. When an owner or contractor submits a request for a variance, the plumbing board shall charge a reasonable fee, payable to the general fund, not to exceed twenty-five dollars. The Building Board of Review shall have the authority to hear appeals from the plumbing board in matters regarding variances and interpretation of ordinances, plumbing code changes, rules, and regulations. The Building Board of Review shall adopt rules governing such appeals.