Except as set forth hereinafter, lot sizes, dimensions and building locations thereon may be freely disposed of, and buildings may be arranged in conformity with the overall density standards set forth herein. No minimum lot size or frontage or maximum lot coverage standards are specified herein, except that in one-family developments, in either conventional tract or cluster layout, no lot shall have an area of less than 20,000 square feet. In reviewing any application for a PRD, the Planning Board shall be guided by standards set elsewhere in this chapter for comparable uses and by common good planning practice, to the end that the resulting development shall be compatible with the surroundings and to assure the stability of the uses proposed to be developed on the site.