It still leaves the problem of people living in much larger houses than they need because it's financially advantageous to do so. Here in the UK older people w

It still leaves the problem of people living in much larger houses than they need because it's financially advantageous to do so. Here in the UK older people with kids who've left the nest often continue to live in large houses because there are a wide range of strong incentives to do so, from low council tax, capital gains tax treatment, inheritance tax treatment, and the protected status of housing wealth for some benefits. The housing crisis could be mitigated to some extent without building any new homes, just by reshuffling the existing stock to people who need the space more. My recommendation would be property taxes that reflect the implicit income you get from living in a home you own i.e the avoided rent.