[zanny]

Sounds like all you need is a primary address exemption. IE, a property needs an associated primary addressee, rather than occupancy. You would not be able to claim a primary address for your second or third home, so if it goes unused it can then be taxed.

[aianus]

Their second, third, and fourth homes are in Shanghai, Beijing, and Hong Kong. I don't think Canada has any access to their land registries.