That the same situation on the normal storehouse. Entrances to work yards and storehouses are on the bottom-right side so the worker has to go around the work yard.
http://i.imgur.com/tFP3UZA.png http://i.imgur.com/wJPOEmM.png
Best placement is top-right or bottom-left
http://i.imgur.com/O5AsgUX.png
1 flag is 2 sec of travel time