While I don't necessarily advocate it, I'd say disqualifying empty buildings from insurance would do more to that end, as no bank or lender will take an uninsured asset as collateral on leverage/debt. The ones who do lend against that uninsured asset will impose interest rates on the debt to where it is cheaper for the owner to just rent the space.
It would be anti-inflationary as well, since it would reduce the amount of free money caused by cheap debt in the economy.
When you see empty buildings, you have to ask who benefits, and in the end, it's always the banks.
Unoccupied buildings generally require different insurance than occupied buildings, and it's often significantly more expensive. Although, apparently, not more expensive enough to balance the incentives to leave property empty.
I don't like most property taxes.
That said, an unoccupied tax makes sence now. I would throw residential apartments, homes, into the mix.
(Single owner properties would be exempt. Realestate investment trusts would be targeted with this tax, along with foreign investors--rich people whom are not citizens whom buy our land, and let it sit.)