Set some limits. Each person can own one primary residence and x number of secondary dwellings. Each additional dwelling is taxed at a higher rate than the one before.
People can still buy themselves a house and maybe another couple houses or condos for their family or investment.
But big landlords can't profitably buy up neighborhoods then crank up the rent. Or perhaps they can own them, but they're required to be non-profits and expenses and rents are highly controlled relative to income in the area.
It's a tough problem to solve though... Huge apartment buildings do have economies of scale that permit high density living.
And property owners who don't sell or develop their land at all because there's not enough incentive are a big problem in other parts of the world.
I really like the idea to tax each house successively more. And the money made from these taxes could specifically go to the government buying houses and turning them into social housing, or perhaps providing big discounts for first home buyers.
But this is exactly the point - the market isn't free, it's being controlled. Primarily by companies that are buying up as many properties as they can.
As long ad there are at least two companies in an area, it will be less profitable for every extra property versus your competitor.
That at least makes hoarding harder, as anyone can come in to out compete the two duopolies as their first will be way more profitable than the established's 11th.
In turn, keeping prices down, scaled by the increase in taxes per extra property
I'd even settle for a law saying that a single corporation cannot own more than one house, duplex, triplex, apartment building (or whatever) in one city. If you want to have a real estate empire across America, fine. You can have your empire be one building per city.
That wouldn’t work unless you also limited the number of corporations an individual can own. The property owners will just have one property in each company, but they will own like 50 LLCs.
See, things like bodily autonomy and right to exist in general are negotiable, but if you try to limit what one man can own, you’re definitely one of them commies!