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 except in conformity with the use regulations herein specified for the district in which it is located.

Except as hereinafter provided, no building shall hereafter be erected or altered so as to exceed the height limit, nor shall any building or land be used or occupied hereafter in excess of the maximum density requirements of article V of this chapter, for the district in which it is located.

Except as hereinafter provided, no building shall hereafter be erected or altered so as to occupy a greater percentage of the lot area, nor shall any side, rear or front yard be narrower or smaller than is required for the district in which it is located.

Except as hereinafter provided, no yard or other open space provided about any building for the purpose of complying with the regulations of this chapter shall be included as a part of a yard or other open space for any other building.