"Unit construction only" Space Yards

[Suicide Junkie]

Hmmm. I'm trying to think of how I could reconcile the "only uses two resources" bit with my "balanced resource use" ideals.

Going with no-organics on the units might work, but that would tend to cripple organic races, since they can't then use organic weapons & such on their units.
No rads usage on units would go against engines and weapons.
Eliminating minerals would just be plain silly.

I'm not sure how I could work that into P&N