Thanks for the reply Gzu, however I do not see a tech tree. The Civilization series offers that, cannot find that in Distant Worlds. Maybe I am just not looking in the right spot.
You should play the tutorial, I'm pretty sure it explains this stuff :)
Edit: In any case, you can find it by going to the Research screen, clicking the Energy & Construction tab, then scrolling to the bottom. You should see something like 'Construction Size'.