Stretch them out, then when they can't refi, foreclose and you have affordable housing, no?
Rental units don't happen because they are expensive to carry. Higher foreign tax is likely racist and won't work (they are much wealthier than Canadians), not allowing foreign purchasers is not very friendly to other wanting to come here. Very nationalistic, do you own a white hood?
Jokes included ^
Now, the best way to reduce house prices? Raise the interest rates to above 5% and leave it there for 2 years.