(a) A permit shall not be required for any of the following:
(1) Any vehicle.
(2) Any structure designed for and used exclusively as a dwelling for not more than four families.
(3) An incinerator used exclusively in connection with a structure described in paragraph (2).
(4) Barbecue equipment that is not used for commercial purposes.
(5) (A) Repairs or maintenance not involving structural changes to any equipment for which a permit has been granted.
(B) As used in this paragraph, maintenance does not include operation.
(b) Nothing in this section shall affect any requirements imposed on a district or a source of air pollution, including, but not limited to, an agricultural source, pursuant to the federal Clean Air Act (42 U.S.C. Sec. 7401 et seq.).