The current rent controls are silly.

Better would have been to do like Paris and simply say that all condos/houses/apartments/business space that sit empty for more than 7.5months a year are required to pay a fee equivalent to 60% of fair market value for that building/space.

That is if you purposely  leave a space empty you pay 60% of market value. The incentive is on all these empty spaces to get filled, thus providing more supply to the market. Paris started at 20% and decided after a few years, that it wasn't enough so raised it to  60% these past few months. 

If anything, it gives municipalities money that they would otherwise have from more people consuming in those neighbourhoods, and can use that for better services to residents.