Facility modules in Homeworld 2 are additional structures built on Motherships, Carriers and Shipyards to unlock the ability to construct additional ship types. Note that some of the ship types also need research performed to unlock them. You can only build at most one of each Facility on the same ship.
Fighter Facility[]
After constructing a fighter facility, both factions are able to construct Bombers.
For the Hiigarans, the facility alloows the construction of Interceptors. For the Vaygr, the facility allows construction of Lance Fighters and Assault Craft
Corvette Facility[]
For both factions, a corvette facility permits the construction of a Minelayer Corvette.
For the Hiigarans, this unlocks the Gunship and Pulsar Gunship. For the Vaygr this unlocks the Laser Corvette, Command Corvette and Missile Corvette.
Frigate Facility[]
For the Hiigarans, this unlocks:
For the Vaygr this unlocks:
Capital Ship Facility[]
NOTE: Carriers cannot build this facility.
Building a Capital Ship facility on a Mothership enables the construction of Carriers, and the Hiiigaran and Vaygr Destroyers. If this is built on a Shipyard, this allows the construction of Battlecruisers