This is actually an amazing idea on so many levels. Everyone wins in this model: improved quality of life for the elderly, better housing for young people than they could afford on their own, improved density for city planners, increased social cohesion.

Unbelievable, I had exactly the same idea a few months ago. To live in a retirement home for a year as a young person, and spend time getting to know the residents, while also going to work at a regular job. I thought it could also make an awesome story for a book or a documentary.

Yes, but that has a decidedly Scandinavian twist of putting young people together with wise village elders. It has a kind of sheen of hopefulness that we just don't see in the States (because -- as clearly demonstrated with this dorm idea -- apparently profit here is worth cramming adults into Soviet-style people storage with value-add juice bars).