As some commentator has said, if it's to be rent, then parallel that with an investment portfolio.  And, one factor left out of the "own" calculation is the opportunity cost of not having access to the equity in the home.
Let us say the couple in the Ottawa suburb were lucky enough to have bought for all-cash.  Yes, no mortgage payments; however that all-cash sum of $425,000 is tied up in house equity and not available for investment in financial instruments.