All applicable requirements shall be met at the first time of erection, enlargement, alteration, moving or change in use of a structure and shall apply to the entire structure or structures, whether or not the entire structure or structures were involved in the erection, enlargement, alteration, moving or change in use. Moreover, no building or structure shall be erected, moved, altered, added to or enlarged unless in conformity with this chapter and no building or structure shall be designed, used or occupied and no land shall be used or occupied for any purpose or in any manner other than as specified in this chapter.