We did attempt having my mother live with us at first, before we settled on buying a second place. I like hanging with her, and we have a lot in common. But after 20 years of it just being DH and me, it was quite stressful for three of us in a 1500 square foot house, particularly because she didn't have anything particularly to do. So despite the much larger financial burden, we are all happier with her living in her own place. HOWEVER, in the future, we anticipate that she might have to live with us again. I think it could be managed ok if the house or property was designed correctly...in other words, a truly separate apartment or suite, as opposed to all trying to manage in a typical starter home where only the small bedrooms are each person's private space. So we are aware that in another 5-10 years, a move to a bigger (or at least much differently designed) house might be necessary. So when we plan for our future, this is one thing we have to keep in mind, and I cannot assume we will be mortgage free in our later/retirement years. To compensate, we are stockpiling extra cash to maintain flexibility.