From Rise: The Vieneo Province - The Space Simulator MMO from Unistellar Industries, LLC
Support Structures is a general category of structures that directly affect the output of a colony.
For example, when you first build a mine it will have a 50% efficiency. By the time you have the Processed Storage, a Separator, and all 11 Extractors, even with the population at the maximum of 30 workers you will be down below 30% efficiency. Too many jobs and not enough workers.
At a farm, for instance, this would represent irrigation systems, water towers, wells, and repair garages for harvesting equiptment.
At a mine this would represent a landing pad, tooling shop, security office, and infirmary.