By constructing and upgrading buildings, you get points of Power and additional opportunities for further development of the Town. Each building has its own set of functions which can be increased with each new level. You can construct and upgrade buildings for game resources and Gold as well. 

You can build or upgrade two buildings at the same time if the Hire Craftsman item is activated in your Town.

To upgrade most buildings from level 27 to 31, you need Platinum. You can purchase this item in the Order Store with Personal Points or as part of Bank offers. You can also get it by accomplishing usual Errands.

In addition, you can get Platinum by attacking Alpha Assailants. Success depends on the upgraded Hero’s Skills, conducted Studies, equipped gear, and activated Boosts that increase characteristics that have an impact on battles against Assailants.

To upgrade buildings from level 32 to 40, you need Empire Ingots. You can get these items as a reward for passing checkpoints in Tournaments or purchase them as part of Bank offers.

To upgrade buildings from level 36 up to level 40, you will also need Trophies of Arms.