| Refinery Upgrade 2 | 250 × Logs; 100 × Nails; 1 × Tarp; 10 × Steel | $0 | Max Workers +0 |
| Refinery Upgrade 3 | 5 × Tarp; 5 × Flux; 50 × Wire; 1 × Unrefined Plastic | $0 | Max Workers +1 |
| Refinery Upgrade 4 | 500 × Logs; 200 × Nails; 20 × Steel; 5 × Gears | $0 | Max Workers +2 |
| Refinery Upgrade 5 | 20 × Tarp; 20 × Flux; 200 × Steel; 5 × Unrefined Plastic | $0 | Max Workers +2 |
| Refinery Upgrade 6 | 1,000 × Logs; 500 × Nails; 40 × Steel; 10 × Rope | $0 | Max Workers +3 |
| Refinery Upgrade 7 | 50 × Tarp; 50 × Flux; 250 × Steel; 10 × Unrefined Plastic | $0 | Max Workers +3 |
| Refinery Upgrade 8 | 1,400 × Logs; 850 × Nails; 60 × Steel; 25 × Rope; 5 × Plastic | $0 | Max Workers +4 |