State your desired building(s) and drop the money off, remember that while some upgrades are automatic, others are not, if it is a manual upgrade, don't drop the money off here, go to the carpenter and ask to have it done please ^_^

Rui buys a one season fishing license and pays 500G.

Jiro walks in and pays 300 for two new bedrooms

Kimby walks inside and hands over 200G for a house.

Rui applies for a house, and also drops off 300G for 2 extra room upgrades.