Accessory uses to residential uses. Lawn storage sheds, shelters for pets and other similar accessory structures may be constructed in any side or rear yard, provided that such structures are kept at least three feet from any lot line, and further provided that such structures are kept at least 10 feet from the principal structure. Detached garages may be constructed in any side or rear yard, provided that such is separated from the principal structure by at least 10 feet, and provided that such structure is at least five feet or 10% of the lot frontage, whichever is greater, from the side or rear lot line. However, where such setback for a garage exceeds the yard requirements for the particular zone, then the yard requirements for the zone shall be used in place of 10% of the lot frontage for establishing the minimum setback distance. Also, on corner lots where the principal structure is allowed, by variance, to be closer to the side lot line than required by regulations of the particular zone, the setback in a side yard abutting the street for a detached garage shall be the same as allowed for the principal structure.