Any building that is nonconforming due to insufficient parking may be enlarged, or may be occupied by a use, other than a medical use, which requires additional parking, if sufficient parking is provided for such enlargement or use and the enlargement or use complies with all other provisions of this code. Additionally, notwithstanding the provisions of section 10-3-4100 of this chapter, a building that is nonconforming due to insufficient parking need not conform to the parking requirements of this chapter unless seventy five percent (75%) of the structure has been altered, renovated, repaired, or remodeled within a period of less than five (5) years. The percentage of alteration, renovation, repair or remodel, shall be determined by the ratio of the total surface area removed or demolished to the surface area in existence prior to the removal or demolition. The surface area elements to be included in the determination are: floors, roofs, exterior walls, including door and window openings, basement walls, and foundation walls. Each element shall be considered to have only one surface. An existing building that is nonconforming due to insufficient parking may not be occupied by additional medical uses unless the building has parking for the additional medical uses that meets the parking requirements in section 10-3-2730 of this chapter and the medical uses are permitted pursuant to section 10-3-1620.1 of this chapter or a medical overlay zone. (Ord. 11-O-2602, eff. 2-11-2011)