I know several British Asian families where granparents and families live all under the same roof. Provided that there is enough living space it can work well. The extended family can keep an eye on elderly relatives. Having more than one generation living together helps prevent social isolation.
I know lot of elderly British couples or even single people who live in large 4 bed houses. Their adult children (and their children) live in tiny expensive rented accomodiation because they can't afford a mortgage.
I realise that not everyone would want to live with their parents/ inlaws however it does seem such waste of high quality housing. I doult that my parents or inlaws would let us live with them.
I feel the govement should discourage single occupancy of large houses.