Part 1: Houses Upon opening the Envoy, you'll see the main screen with a lot of Houses. You must occupy a house to generate points. Once you occupy a house, you sit in it forever unless someone with a higher title and/or merit kicks you out. You will be able to occupy any empty house, or one that has a player with a lower title and/or merit than you have. It's best to find a level of house that other players won't steal from you. If you sit in a house that's higher than your title/rank/merit can support, then you'll be kicked a lot. You only get 3 snatching chances per day.
Part 2: Rooms On the right, left and bottom of the main screen you'll see 'Book House' 'Wealth House' and 'Official House' Click on these to take you to different kinds of rooms. These rooms earn you different things. Book rooms earn you Book exp, Wealth rooms earn you Alliance Wealth, Official rooms earn you Merit. These rooms reset every day at 11AM server time, so you'll have to use the points generated in your house to sit at several rooms every day. You will dispatch retainers to guard these rooms. Another player can steal these rooms from you if they have stronger retainers than you have dispatched to that particular room.