Forbid corporate ownership of anything under 4 units/12 bedrooms, and require them own 100% of any contiguous building over 4 units. Added taxes will just be passed on to residents. Corporations are used to aggregate money (both public corps and family/friend groups) and avoid taxes.

Then make a financial law that forbids making property loans with collateral which includes any real property that is not the property being purchased. No condo bros buying units and then re-fi-ing out to buy more.