不會丟home exemption，加拿大比美國好多了，

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/personal-income/line-12700-capital-gains/principal-residence-other-real-estate/changes-use.html

Every time you change the use of a property, you are considered to have sold the property at its fair market value and have immediately reacquired the property for the same amount. You have to report the resulting capital gain or loss (in certain situations) in the year the change of use occurs.

也就是說，他們把自住房出租的那一年，要清算自住房的增值，然後重設出租房（同一個房子）的基數。所以以前的自住房增值馬上就可以兌現免稅。

所以我再罵他們，這麽多錢的事情，不去當地找專業谘詢，而到網上來瞎問。有錢也要被折騰掉。