X-Com Structures
Command Center
This is where all communications to the committee of funding nations take place. The committee will give you additional funding periodically. Without your command center, you will be unable to construct new facilities.
Power Plant
X-Com facilities need power. Some buildings, such as radar and defenses, will not function without power.
= Command Center
Elerium Refinery
In order to reproduce alien technologies you must have Elerium. The refinery allows you to use Elerium harvested from crash sites.
= Command Center, Power Plant
Living Quarters
Before you can enlist any new soldiers, you must provide adequate accommodation.
= Command Center, Power Plant
Radar
Your radar system provides you with an aerial view of the battle field, helping you to locate alien incursions quickly. Once you have constructed this facility, you will have access to the Spy Plane which can reveal unexplored areas of the local terrain.
= Command Center, Power Plant, Elerium Refinery
Workshop
The workshop constructs the majority of your vehicles and is needed for the assembly of new technologies.
= Command Center, Living Quarters, Elerium Refinery
Air Force Command
The Air Force is Earth's mainstay against the alien forces. With the Air Force Command, you have access to jet fighters and greater fire power for your struggle against the alien menace. Once you have constructed this facility, you will have access to a Napalm Airstrike and you will also be able to call in a paradrop of GIs periodically.
= Command Center, Living Quarters, Radar
Repair Depot
The Repair Depot can repair damaged vehicles. Any units docked with the depot can be sold if you have a Command Center.
= Command Center, Workshop
Laboratory
With the aid of a research laboratory, you can research new and alien technologies that could give you the upper hand against your new foe.
= Command Center, Workshop, Air Force Command
Elerium Power Rod
Your Power Plants can be upgraded to produce extra power with an Elerium Power Rod.
= Command Center, Laboratory, Power Plant
Requires stolen Alien technology.
Hyper-Wave Decoder
The Hyper-Wave Decoder can intercept enemy communications and alert you to enemy targets within its area of effect. Once you have constructed a Hyper-Wave Decoder you no longer need your old Radar facility.
= Command Center, Radar, Laboratory
Requires stolen Alien technology.

X-Com Armory
Concrete Slab
Concrete Slabs give your base a firm ground for your units to move on as well as providing defense from subterranean assault.
= Command Center
Concrete Wall
Concrete Walls form a strong barrier that most units cannot cross and must either break them down or go around.
= Command Center
Pill Box
Pill Boxes are manned machine gun emplacements that provide a good defense against enemy troops.
= Command Center, Living Quarters
Patriot Missile
The patriot missile platform is an effective defense against enemy air and ground units.
= Command Center, Air Force Command