No person, firm or corporation shall erect, construct, enlarge, alter, repair, move, improve, convert or demolish any building or structure within the city, or cause the same to be done, without first obtaining a permit for such building or structure from the building official. Separate permits are required for grading, electrical, plumbing, mechanical, and low-voltage. However, a homeowner is exempted from obtaining a building permit for remodeling and/or improving his or her dwelling or property as long as the cost of the construction materials does not exceed $1,000.00, and the work is begun and completed solely by the homeowner. This exemption applies only to nonstructural changes (refer to the definition of “Structure” in the city zoning ordinance) and does not apply to any activity which changes the square footage of a structure.