"Lot coverage" means the footprint of the structure or structures divided by the actual area of the subject lot. For those lots which include tidelands, lot coverage shall be based on the area of the subject lot upland of the ordinary high water mark. The area of any uncovered and unenclosed deck or parts of a deck which are less than eighteen inches above the existing grade, and at-grade patios shall not be included within the lot coverage calculation. (Ord. 01-412 §1 (Exh. 1 (part)), 2001)