Except as herein provided:

1.   No building or structure shall be erected or structurally altered, nor shall any building or land be used, which does not comply with all of the district regulations established by this chapter for the district in which the building or land is located.

2.   No lot shall be reduced in dimension or area below the minimum required by this chapter. No part of a yard or other open space, or off-street parking or loading space provided about any building, structure, or use for the purpose of complying with the provisions of this chapter, shall be included as part of a yard, open space, or off-street parking or loading space required under this chapter for another building, structure, or use.

3.   Every building hereafter erected or structurally altered shall be located on a lot herein defined and in no case shall there be more than one principal use structure on one lot unless otherwise provided in this chapter.

4.   No building shall be erected or shall be structurally altered to the extent specifically provided hereinafter, except in conformity with the off-street parking and loading regulations of this chapter.

5.   No lot shall be reduced in dimension or area below the minimum required by this chapter without first obtaining a certified survey.