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.
That would require making more land and increasing the capacity of existing high-use, aging infrastructure for water, sewage, power, and trash. I can find you a cheap place to live out in the sticks. Hell, the town down the road from me has brand new, 3BR 2.5BA 1900SF homes with garage for $270k (USD). You only need 2BR/1BA and 1100SF? $150k. Thing is, it’s a 30-40 minute drive to the center of my 200,000 person MSA. But this isn’t a fun, entertaining city with excellent walkability, public transit, a major airport, and multiple concert venues and public spaces so people aren’t flocking to move out here.