How the game proceeds after all the properties, houses and hotels already bought?
Building shortages are part of the strategy of the game and it is intended that players might not be able to buy houses because of a lack of them in the bank. It is also intended that when a player has to sell a hotel they also have to sell all all houses as well if there are not enough in the bank.
When the Bank has no houses to sell, players wishing to build must wait for some player to return or sell his/her houses to the Bank before building. If there are a limited number of houses and hotels available and two or more players wish to buy more than the Bank has, the houses or hotels must be sold at auction to the highest bidder.