All required yards shall be situated on the same lot as the building or structure to which it applies. No required yard area or other open space around the existing building that is needed to comply with the setback or open space requirements of this title shall be considered as providing the required yard area or setback or open space for any other building; and no required setback, yard area or other required open space on an adjoining lot may be considered as providing the setback, yard or open space on the lot where a building is to be erected or constructed. (Ord. 6-20-78A, 6-20-1978)