Canada

Just limiting how many properties a person/corporation can own would solve the problem alone. Tax should exponentially increase after 2+ properties.

Make coop housing viable, currently it's almost impossible to start one.

Gov should be building housing too, just like the ww2 houses: https://en.wikipedia.org/wiki/Strawberry_box_houses

In addition, feds should be building housing to house every single person, unconditionally. On the topic of homelessness it's the only way to reintegrate folks into society. Even if, say, 80% do nothing but shoot up in their free housing, it's still cheaper for taxpayers when you consider the cost of taking care of folks on the street and the problems that causes. And just by building housing stock you're making good entry level jobs that don't require university education.

And this may be controversial, but non-Canadians should pay a higher mortgage rate. Finland does this and they have probably the best housing situation on the planet. They are actually the ones who pioneered the idea of unconditionally housing everyone, IIRC.

Canada has built roughly the same number of houses per year since the 90s.

Yes but we also weren't taking 1 million newcomers per year in the 90s. If you want these immigration numbers you need to have a plan to make it work.