Except as previously or hereinafter provided, it shall be unlawful to relocate, erect, construct, reconstruct, enlarge, structurally alter, or use any buildings, structure, or land except in conformity with the regulations of the district in which such building or structure is located or in accordance with Sections 26-75 (Exceptions and Modifications). (See also Section 26-24 (Nonconforming Uses, Buildings or Lots))