No construction permit shall be issued for any parking lot designed for four or more vehicles, new structure, or modification/addition to an existing parking lot or structure until the site plan has been reviewed and approved by the Planning Board (or Zoning Board) except that: (1) a construction permit for a single or two-family dwelling and its accessory building(s) on a lot shall not require site plan approval; and (2) any addition or alteration to an existing conforming nonresidential structure which does not account for more than 10% additional lot coverage shall not require site plan approval if, in the opinion of the Construction Official, such addition or alteration will not create nuisance problems to adjacent land uses. Where site plan approval is required, the Planning Board (Zoning Board) shall review the proposal, determine whether or not the applicable standards provided by this Chapter have been observed, note objections to such parts of the plans as do not meet the standards, suggest corrections and recommend desired changes to effect compliance with the chapter, and be satisfied that the site plan represents the most desirable alternative for development of the site in compliance with the chapter, and when satisfied that the site plan complies with the requirements of this Chapter, shall approve the site plan.