No outbuildings, sheds, garages, enclosed outdoor storage facilities, or other similar structures shall be erected, placed or maintained on any lot within the property unless such structures are (i) constructed of material other than metal; (ii) are located only in the rear yard of any lot; (iii) do not exceed the aggregate size of ten (10) feet by twelve (12) feet above ground level; (v) are built in accordance with plans, specifications and illustrations approved by OPF.