Armory
Barracks
Bunker
Command Center
Has the ability to carry up to five SCVs and can upgrade to the powerfully armed Planetary Fortress.
Planetary Fortress
This immobile upgrade of the Command Center greatly increases its power and grants it weapons to attack enemy ground units.
Surveillance Station
This immobile upgrade of the Command Center increases its sight range and enables scanning of troop movements through the fog of war.
Engineering Bay
Factory
Missile Turret
Loses its detector ability and relies on the Sensor Tower to grant it detection. It also fires two missiles at a time instead of one.
Refinery
Starport
Supply Depot
The new Supply Depot can submerge, enabling troops to walk over it. It is smaller and can be made into an important part of Terran base defenses, preventing enemy units from walking past them.
Deep Space Relay
This structure allows production of Battlecruisers and provides researches for them.
Merc Compound
This structure acts as a requirement for producing Reapers.
Munitions Depot
This structure allows production of Thor by SCVs and provides researches for them.
Sensor Tower
This structure can detect enemy units at long range, even within the fog of war.[79]
Shadow Ops
This structure enables Ghosts to be produced and provides researches for them. In addition, it stores nukes and Drop Pods for launch.
Radar Tower
This building can sense enemy units, even if they are moving in unexplored terrain. However, it is exposed to the enemy, which can avoid its sensing area while rushing to the base.
Add-Ons
In StarCraft II, Terran add-ons work quite differently. There are only two add-ons which have been described, the Nuclear Reactor and the Tech Lab. Instead of being specific to an associated structure, each add-on can be added to any Terran unit-producing structure (Barracks, Factory or Starport), granting a specific benefit. One structure may only have one add-on attached to it, so it cannot benefit from the Reactor's bonus and the Tech Lab bonus simultaneously.
Nuclear Reactor
When added to a Terran structure, this doubles the number of units produced from a building. (For instance, adding one to a Factory will enable it to create two Vikings at the same time).
Tech Lab
When added to a Terran structure, this enables the production of "higher tech" units. For instance, adding a Tech Lab to a Barracks will allow it to produce Medics, while adding one to a Factory will enable it to build Siege Tanks.