I like to play one family meaning all my households have an relation to each other, it really depends on the story I'm doing, I tend to make my teens as teeny as I can go in the sims 4 they still stay with mum and dad at that point and have a curfew at 11pm, when I want them to move out it's normally when they reach young adult, some go to university I either have them live in a dorm or still stay with mum and dad at that point, I once done a story of an young adult sim still staying with mum and dad without a job etc lol in that story I made the mum and dad very frustrated with them that they always party and sponge off them, I done a bustin out story ( got the idea from the sims bustin out)