https://replay.faforever.com/18156522
11:30 minutes for Kye3k1 upgrading T3 Navy HQ. Watch the behaviour.
I was upgrading the right side Navy HQ Factory from T2 to T3. Despite eventually pausing all my production the factory (unassisted) still used 60 mass per tick.
You can see the game mass/energy overlay shows the upgrade using 60 mass even when paused.