There is explanation somewhere in help, I saw it. But I did not understood it after reading a few times. Actually, I wanted to build an asteroid base. Acording to my understanding, building bases should give up these points. But when I tried - I've got a message, that I have no enough construction points.
Basically, higher tier buildings have two requirements:
- Available construction points of the appropriate tier; and
- Prerequisite buildings.
So as an example...
Available at Tier 1 there's a Relay Station facility. Building it will give you a Tier 2 construction point.
Also at Tier 1 there's an Agricultural Farm. Building it will also give a Tier 2 construction point.
At Tier 2, there's a Security Station. This will consume a Tier 2 construction point,
and has the Relay Station as a pre-requisite. Building it will give a Tier 3 construction point.
At Tier 2, there's a Government station. This consumes a Tier 2 construction point, but has no pre-requisites.
At Tier 3... dunno... looks like you can only see them once you have a Tier 2 facility built.
So if you build a Relay Station, you get a T2 point, and could build
either the government station or security station, but not both.
If you build an agri farm, you get a T2 point and could build the government station next, but not the security station, as the pre-req isn't satisfied.