I play legacies in all my saves. Even if they don't start that way, they inevitably turn into it haha. Almost always I will choose an heir by the time the kids are teens. The heir, if they even go to uni, will attend while living at home with the parents. After graduation they move back into the family home. The non heir children are given a home of their own when they age to YA and move out. The heir starts spouse hunting and the spouse moves in with the heir and their parents. I can't see the benefit in moving out a couple of adults or elders (depends) who are usually by this time maxed out in very useful skills like cooking, handiness and especially parenting. I might move grandma and grandpa out to their own little cozy home once the kiddos are child age. Sometimes they stay in this 3 generation home until they die.
