- The Firebase is the main UNSC structure. It starts with only 3 building sites.
- The Firebase is upgradeable to the Station Level. This level has 5 building sites, and four Turret Sites. Costs 300 Supplies to upgrade, and 0 Tech Level.
It can then be upgraded to the Fortress Level, which adds 2 extra building sites.
No matter what UNSC Leader you play as, the Warthog is buildable along with a certain unit. (Anders Gremlin/Cutter's Elephant/ Forge's Cyclops) All Warthog upgrades are researched from here.