If a player has the <a action="GoToPage" data="Companies_Ranks">permissions</a> to do so, they can build Structures in any <a action="GoToPage" data="Companies_Territories">Territories</a> that their Company owns. Building is done by first placing a Blueprint, then supplying the required resources.
To place a Blueprint, enable Build Mode. Using Build Mode, you can navigate possible Blueprints using the mouse wheel. When you've found what you want to build, move to where you want the Structure to go and place it, much like you do with your <a action="GoToPage" data="Mechanics_Camping">Camp</a>. You can only place Blueprints up to the same Tier as the Territory's Protection Ward.
Once placed, you need to supply the Blueprint with material to actually construct it. These resources are supplied from your <a action="GoToPage" data="Mechanics_Inventory">Inventory</a>. They do not have to be added all at once, allowing you to make multiple trips.
Structures that can be used, like <a action="GoToPage" data="Crafting_Refining">Refining Stations</a> and Storage Containers, can have a minimum rank set to use it. In order to set this requirement, interact with the Structure yourself and use the dropdown menu at the top of the screen. Most Structures can have this permission set to any rank or even be opened for public use. A Structure with its permissions set to public can be used even by players outside of the Company that owns it.
To repair or demolish a structure, approach its interact point and press the key for More Options. This will allow you to select what you want to do using your mouse.