For the purpose of ascertaining whether any sign is no more than the dimensions permitted by this article, the gross sign area shall be the entire area within a single continuous perimeter enclosing the extreme limits of such sign, and in no case passing through or between adjacent elements of the same. For measurement of gross sign area, such perimeter shall not include any structural elements lying outside the limits of such sign and not forming an integral part of the display. In the case of an open sign, made up of individual letters, figures or designs, the space between such letters, figures, or designs shall be included. The total area of both sides of a double-sided sign, including V-type signs, shall be included in the computation of gross sign area. Signs which are composed of letters, words, or representations only and which do not form a square or rectangular pattern shall be considered to include in gross sign area a square or rectangle as drawn at the outer limits of the letters, words, or representations.