I have instead started mass producing engineering brigades. This is an incredibly efficient way of servicing a frontier colony with building capability. They don't require any population and in terms of build points, they are only slighly less efficient than construction factories for the same amount of construction capacity. They use vendarite instead of duranium and neutronium, which can be an advantage if you have a crunch and I never seem to use all my vendarite. They also allow you to construct them in parallel to construction factories since they use different facilities and won't take up construction capacity to build your mines, for example. For most colonies I would probably ship around 200.000 tons of vehicles with construction modules as a start. I don't have the numbers on me right now, but this was often enough to get started. Then as I build construction factories, the engineering brigades could be redistributed to newer colonies.

Excellent thank you - what does a spaceport do?