Except as hereinafter provided, no building or land shall hereafter be used or occupied and no building or part thereof shall be erected, moved or altered unless in conformity with the regulations herein specified for the district in which it is located.

No building shall hereafter be erected or altered to exceed the height, to accommodate or house a greater number of families or to have narrower or smaller rear yards, front yards or side yards than are specified herein for the district in which such building is located.