Section 502(f) of the guidelines adopted in section 90-166 is amended to read as follows:

(f) Under-floor clearances, ventilation and access. A minimum clearance between the bottom of the floor or floor joists and the ground shall be 30 inches. Under-floor spaces shall be ventilated with openings as specified in the building code. Combustion air for heat-producing appliances shall not be taken from within the under-floor spaces. Under-floor access openings shall be provided. Such openings shall not be less than 18 inches in any dimension and not less than three square feet in area and shall be located so that any water supply and sewer drain connections located under the manufactured home are accessible. Access openings to under-floor spaces containing equipment shall be large enough to remove the equipment without dismantling, with a minimum size of 30 by 30 inches.