The modifier (mod) gives a permanent bonus to the characteristic of the building. To get this bonus, you need to open the building and place the mod in the appropriate slot. The building has 6 modification slots, 1 for each type.
You can get the mod from a monster, buy it in the store or obtain it from the Factory construction.
modification types
Increases building Gold Capacity and protects from stealing.
Increases building HP.
Repairs a building before it burns down once.
Expands building Storage.
Increases building HP Regen.
Increases building Income per second.
