No land shall be used for a purpose except as permitted in the district in which it is located.

No building shall be erected, converted, enlarged, reconstructed, moved or structurally altered, nor shall any building be used, except for a use permitted in the district in which such building is located.

No building shall be erected, converted, enlarged, reconstructed or structurally altered except in conformity with the area regulations of the district in which such building is located.

No building shall be erected or structurally altered to the extent specifically provided in this chapter except in conformity with the off-street parking and loading regulations of the district in which such building is located.

The minimum yards, parking spaces, and open spaces, including lot area per family, required by this chapter for each and every building existing on the effective date of this chapter, or for any building erected after that date, shall not be encroached upon or considered as part of the yard or parking space or open space required for any other building, nor shall any lot area be reduced below the requirements of this chapter for the district in which such lot is located.

Every building erected or structurally altered after the effective date of this chapter, shall be located on an individual platted lot; and, except as otherwise provided, there shall not be more than one main building on one lot.