I think you can build a house with rooms for different sims and get roommates to move in. The roommates are sims who live in your house but you don't control them. I don't use tggem myself because they use up all of tgecspare places in the household so you always have 8 sims living in the house. I wanted to be able to specify how many roommates would live with me. So I dont use that system now. I do have houses full of unrelated sims as housemates and play them occasionally.