The Service Buildings initially come with one slot for one visitor. Next to the slot, there is a green arrow that indicates the possibility for an upgrade. Each building has four different categories which can be upgraded:
Tapping on the “+” icon under each category brings up a list of Expansion and Upgrade Materials that you need to complete the upgrade. These materials include Brick, Hammer, Hand Drill, Paint Bucket, Stone Block, Tar Bucket and Map Piece. Keep in mind that you will need the normal materials from your Farm as well.
Typically you cannot upgrade all categories to the maximum level at once, except that you’ve reached Reputation level 38. New upgrades are allowed as your Reputation level progresses.
Tap the button below!