We have been thinking along those very lines at the moment. My youngest daughter wants me and my husband to live with them at some point, so that when one of us dies, the other one won’t be alone. At the moment, they have their own house, and one baby, but want more children. They’ve talked about buying a house with a separate annex for us. We’re both 60 at the minute, so don’t feel quite ready, but we have said that if one of us dies before we’ve managed to move in together, how would they feel about moving into our house, which, like you, is far too big for two of us let alone one. We suggested they could rent their own home off. They liked the idea. We would have to put something in place, so that if both my husband and I died, if we were still in our house, then they would probably have to sell it, so my other three children get their inheritance, but there would be no rush. I suppose I hadn’t thought about the rowdy teenager stage, but then we would hopefully, long term, be in something more suitable, ie have an annex. I would definitely try it first, before you sell it, and see how you get on. If you can divide rooms etc, and living spaces, which it sounds like you could, I don’t see why you should lose your independence. After all, at the moment, they’ll be moving in with you. Good luck.