best barns new castle 12' x 16' wood shed kit best barns inc. the new castle shed kit provides plenty of storage. just the right size for any backyard and big enough for storing your tools and household items and still have room for lawn and garden equipment. the 5′-4′′ wide door opening can accommodate your riding mower or four wheeler. doors can be placed either right or left of center during construction. this is for the wood shed kit only. this does not include the floor kit; windows; roofing and cupola.