Like there's a module within the buildings module group, that generates income, but is sorta expensive (relative to income) and weak/big (5x5 or smthing). eg. farm/ factory module.
In conquest, cities are initially supplied with those, and that determines their income. One can place those income buildings to further boost income, at the cost of a large short term loss.
The limit of how many of those income things (in the long term) you can place would be the available space you're willing to sacrifice, as they are pretty big.
Or even make buildings with those income things unable to have weapons or something.
So you mean civilian buildings? Zark has mentioned the possibility of those in Dev 10.
Air Lord, Engineering Corps
I'd really like to see buildings have a 'capital city' tab that houses a lot of specific 4x4 and bigger modules that do things like that or are just very big guns and they all buff one another from being in the same building. The idea is that players/the AI would construct huge city capital buildings for you to conquer.