The approval of a petition and consequent amending of the Zoning Map by overlay of the CPD District shall be based on and include as conditions thereto the building, site and operation (BSO) plans for the development as well as all other commitments offered or required with regard to project value, character or other factor pertinent to assuring that the project will be developed basically as presented in the official submittal plans as approved by the Common Council and shall be mapped and recorded as provided for conditional uses under Article XIV of this chapter. Such plans, however, need not necessarily be completely detailed at the time of overlay zoning, provided that they are of sufficient detail to satisfy the Plan Commission and Common Council as to the general character, scope, and appearance of the proposed development. Such preliminary plan shall at least designate the pattern of proposed streets, the basic pattern of land use, and the size and arrangement of lots and illustrate a "typical" example of the development proposed. The approval of such preliminary plan shall be conditioned upon the subsequent submittal and approval of more specific and detailed plans as the development progresses.