Copypaste from documentation:
facilities:
- type: STR_SOME_FACILITY
buildCostItems:
STR_ITEM:
build: 10 #how many items of type `STR_ITEM` are require to build.
refund: 6 #how many items are returned when facility is dismantled.
provideBaseFunc: [ A ] #List of custom IDs that this bulding provide for base.
requiresBaseFunc: [ ] #List of custom IDs that are require to build this building in base.
forbidenBaseFunc: [ B ] #List of custom IDs that are forbiden by this building.
trainingRooms: 0 #Number of solder that can be train in that building, require langue strings.
refundValue: 0 #how much mony is returned when facility is dismantled.