What is the difference, upgrade honor in AC1 and AC2?

The honor structure buildings are all the same regarding the benefits they give at each level. However in the current doomsday event the costs for upgrades tend to be higher for the higher AC buildings than the lower ones.

This means it will cost more materials and resources to do upgrades on AC 3 or 4 located structures than it does on the ones at AC1 / 2