Building your asteroid colony is one of the key parts in Age of Asteroids. In the early stages of the prototype this was a bit confusing and in my opinion not very intuitive .. and it was slow, because of how the old system tried to do most of thw ork for you - you've readen more about that in the last news.
Whatever. In order to have proper construction logic, there has to be some sort of building order, building animations and - of course - a visual representation about the progress of the building process.
How does building work in general
To construct any building you need a construction facility module. Those will be able to construct one building at a time and also will be responsible for repairing or reconstructing damaged modules. You can build more construction facilities to build more concurrent projects and there will be some more sophisticated building types (like the orbital station or space dock) where you will need multiple construction facilities to start building at all.
Because there are actually men working to construct your building jobs, they can only start it when they are able to reach it which gives your building jobs a distinct order in which your jobs are fulfilled.
In case of enemy approach you may find yourself in a battle which can quite damage your whole colony. Even when you defeat the engagers, you may need some time to recover and let your workers repair your damaged or destroyed buildings. A destroyed building will not function leaving you with a lack of energy, food, water or workers and soldiers.
So your best bet is, to get your colony up again as fast as possible before another enemy is taking his chance.