Buildings are the heart of your Command Center. You need buildings to perform activities, learn new abilities, and function within the game. As you increase the level of your buildings you can learn more powerful skills, train more powerful troops, and create resources at a greater volume.
To learn what a particular building does, click on the building then click "Details".
When you first start out, upgrade your buildings to the maximum level allowed by your HQ level.
Sometimes upgrading a building requires you to have another building at a certain level as a prerequisite. When you try to upgrade a building that has a prerequisite that you haven't met, that prerequisite will be highlighted in red text at the top of the list of build requirements. There will also be a button to go to that building so you can achieve the prerequisite.
Air Force Command Center (HQ lvl 12)
Prison (HQ lvl 26)
Flag (HQ Level 12)
Arms Dealer / Fortune Wheel
Air Force Factory (HQ lvl 12)
War Game / Recruit Room