But what happens if you just chop down SFH and rebuild with higher density, and you don't also put restrictions on investing in the new units? You just end up with the problem we have now. We're building tons. Our local GDP is largely based around real estate. Not that we don't have a NIMBY problem — but there's only so much building you can do before you look around and feel like you just built more empty houses for people who don't live here.
Though, it seems like a condominium complex that is 50% empty would give you a greater density of neighbors than a SFH suburb that is 50% empty. And you can get the Chinese to pay for your new roof, to boot.
Somehow I doubt even the Chinese have enough money to turn a high-density city into a scene from 28 Days Later, though.
I don't know enough about Canada to say why they have restrictive zoning laws. In the US, it's mostly government-backed mortgage programs and covert racism.
I don't care how rich the Chinese are; those properties would be demolished, rebuilt as apartments, and rented if it were allowed. Because the value of the property is directly proportional to its expected profit. It's only when the government disconnects the two that you ignore the rental profit. The Chinese government's currency controls probably don't help, either: The Chinese are willing to lose money as long as it's free from their government's currency controls.
Does Canada offer government-backed loans that are available to foreigners?