“Side yard” means a yard extending from the rear lot line of the front yard to the rear lot line, or in the absence of any clearly defined rear lot line to the point on the lot line involved with the public street. In the case of double-frontage lots, side yards shall extend from the rear lines of front yards required. If no front yard is required, the front boundary of the side yard shall be the front property line. (Ord. 454 § 4, 1992)