Command & Conquer/GDI structures

Power Plant

 * Cost 300

These structure provide power to bases.

Refinery
Cost 2000

Provides a Harvester to seek out Tiberium to gain cash. Build more than one for good things to happen.

Barracks

 * Cost 300

Trains infantry

Advanced Power Plant

 * Cost 700

Same as Power Plants only provides more power.

Helipad

 * Cost 1500
 * Unusually short build time.

This structure is used to make Orcas for GDI and Apaches for NOD, and includes one such aircraft along with constructing the helipad. When an aircraft runs out of ammo, it will automatically return to the helipad to rearm itself.

In a multiplayer game, they may also produce chinooks to transport units.

Weapons Factory

 * Cost 2000 what to expect from a factory

Used to make tanks.

Repair Bay

 * Cost 1200

Used to repair tanks

Advance Communication Center

 * Cost 2800

Used for ION Cannon controls and radar. It also provides more advanced tech options such as the commando, SSM and MCV.

Communications center

 * Cost 1000

Provides Radar.

Advance Guard Tower

 * Cost 1000
 * Range Long
 * Weapon Missiles

This thing has good weapons and armour.

Guard Tower

 * Cost 500
 * Range Medium because Artillery can destroy it
 * Weapon Guns

This thing has chainguns for enemy engineers.