What buildings are benefited by adjacency to workshops?
What are the proximity bonuses for adjacent buildings and when do they apply?
I know that building anything beside a workshop gives an immediate benefit upon completion in the way of a 7% rebate on the cost of the building.
Which buildings receive ongoing rebates thereafter? Foundry? Psi Labs? Officer Training?
I've noticed I get that green linking
+icon if I build two adjacent workshops, but I can't figure out what is for.
The green plus sign is the adjacency bonus. The more of these you have between workshops, the bigger the rebate you are going to get. Building a facility other than a workshop next to your workshops will not benefit you.
As the tooltip says, you will get rebates depending on the number of your adjacency bonuses when building vehicles, facilities and foundry projects.