Cornices and eaves, chimneys and bay windows shall not project more than two feet into any yard setback required by zone. In no event shall any cornices, eaves, chimneys and/or bay window projection be any closer than eight feet to any side yard lot line or result in the enlargement of any nonconforming structure. Additionally, no chimney projection into a yard setback shall be larger than 10 square feet on a lateral plane.