The Warehouse is a Covenant structure featured only in Halo Wars.
The Warehouse is a Covenant building used for collecting/processing resources. It can be built onto any unused Covenant or Neutral plot, for 100 resources where it brings down supplies from orbit to Covenant bases via gravity lift, from which workers move the supplies to the proper area for further use by the Covenant commander. At tech level 1 it can be upgraded to a Blessed Warehouse for 225 resources to allow for faster collection of resources. The normal warehouse produces 240 resources per minute and the blessed warehouse produces 330 resources per minute. It is the Covenant equivalent of the UNSC Supply Pad. [1] In order for a Warehouse to be upgraded, a Temple must be built.
The difference between the normal and "blessed" variant seems to be that the blessed variant is more advanced than the normal one, and looks more intricate, has a larger sliding section and four more storage tanks. Obviously, this contributes to the doubling of the resource gathering rate. It seems obvious that both variants are made repurposed by Forerunner technology, as seen by the forerunner-like structure. It can be believed that the Covenant modified this technology to become a "warehouse".