Board Thread:Questions and Answers/@comment-75.80.54.20-20140401142915/@comment-4721245-20140404132650

Technically you need a minimum of three warehouses, but due to tactical module and retrofit requirements you may need all five warehouses at level 12. You could get well fine with four warehouses or three however you had better plan your retrofit or tactical module research time well with your shipyard build times so that you can use the resource overfill after canceling Hugh ship builds (assuming your ship build does make use of so much resources).