The broadest solution is very high property taxes - ideally a land value tax - in order to encourage productive use of property and limit speculative bubbles.
Well by those terms, the more tax you owe on a property the more productive either it and/or you have to be to maintain it - as the taxes increase, so do the incentives for you to put the property to work (as a rental), so that it helps to cover the cost of its own existence. It's similar to the incentives around NIT in Europe - if you have to pay money to the bank for them to store your Euros, you have more of an incentive to find productive capital investments instead.
So the more expensive a property I have, the more pressure should be put on on me to rent it out? If I own a hovel I get to keep it to myself but if it's George Clooney's villa on Lake Como or Zuck's house in Palo Alto society should lean on them to make these places "productive" by renting them out?
Yes, I think there should be pressure to either use it yourself (if you decide your personal utility is worth the cost) or to rent it out. You can still leave it empty, of course, but people do respond to incentives; the more the maintenance costs, the more incentive they will have to either use it themselves, or rent it, or sell it. One of the major problems is that many of these properties currently sit empty as a store of wealth - like a safety deposit box - for overseas owners, which causes problems for the community.