The Iron Warehouse raises protected iron quantity. It requires Base level 10 for construction and has 30 building levels. Iron production belongs to the Iron Mine, a separate building.
How the protection value works
A level 1 Iron Warehouse provides 900 protected iron. The amount rises to 180,000 at level 10 and 9.9 million at level 20. At level 30, it reaches 225 million.
The listed value is the protection at that level, not a quantity of iron produced or paid out. The extra protection from an upgrade is the difference between the old and new values.
Resource-specific protection
The Food Warehouse has its own protected-food stat, while the Coin Vault covers coins. Developing one resource's warehouse does not replace the other two.
Research also includes bonuses to protected food, iron and coin quantities. Those effects come from completed technologies, while the Iron Warehouse's contribution follows its building level. Production, protected quantity and the amount required by your next upgrade remain separate figures.
