These regulations are to encourage and provide means for effecting desirable and quality development by permitting greater flexibility and design freedom than that permitted under the basic district regulations, and to accomplish a well-balanced, aesthetically satisfying city and economically desirable development of building sites within a PUD. These regulations are established to permit latitude in the development of the building site if such development is found to be in accordance with the purpose, spirit and intent of this chapter and is found not to be hazardous, harmful, offensive and otherwise adverse to the environment, property values or the character of the neighborhood or the health, safety and welfare of the community. It is intended to permit and encourage diversification, variation and imagination in the relationship of uses, structures, open spaces and heights of structures for developments conceived and implemented as comprehensive and cohesive unified projects. It is further intended to encourage more rational and economic development with relationship to public services, and to encourage and facilitate the preservation of open lands.