(a) No building shall be erected, reconstructed, relocated or structurally altered so as to have a greater height or bulk, a higher percentage of lot coverage or smaller open space about it than is permissible under the limitations set forth in this Zoning Code for the district in which such building is located, except that parapet walls, chimneys, cooling towers, elevator bulkheads, fire towers, stacks, stage towers, scenery lofts and necessary mechanical appurtenances shall be permitted to exceed the maximum height provision when erected in accordance with all other ordinances of the Village.
(b) No space allocated to a building or dwelling group for the purpose of complying with the side, rear or front yard or court or other open space or lot area requirements of this Zoning Code shall thereafter by reason of a change in ownership or for any other reason be used to satisfy the yard, court, open space or lot area requirements of any other building or dwelling group.
(c) No usable open space or off-street parking space or loading space existing or provided hereafter for any building shall be reduced below the minimum requirements set forth for such usable open space, parking space or loading space, nor be further reduced if already less than such minimum requirements.