Do I have to self-assess HST if I keep my newly built home as a long-term rental instead of selling it?

Generally, yes. Under the Excise Tax Act's self-supply rules, someone who builds or substantially renovates their own home and then, instead of selling it or moving in as their primary residence, starts renting it out is generally treated as having sold the property to themselves at fair market value and immediately bought it back, triggering an obligation to self-assess and account for HST on that value, even though no sale to a third party actually happened.

This surprises a lot of owner-builders, who assume HST only comes up if they sell the property, not if they simply decide to rent it out instead. The self-assessment is meant to put a builder who becomes a landlord in roughly the same tax position as someone who bought a comparable new rental unit from a builder and paid HST on the purchase price up front.

Once the self-assessment is done and the HST is accounted for, the New Residential Rental Property Rebate may be available to recover part of that amount, provided the rental use and paperwork qualify. Because the timing of the self-supply, the valuation used, and the available rebate all interact, this needs to be calculated properly with an advisor around the time you start renting the unit out, not left until later.