Ontario Builders Can't Claim HST Relief Yet—So They're Paying for Temporary Fixes Instead

The law is on the books. The regulation isn't. That gap has become the single most expensive pause in Ontario's housing industry right now.

Ontario passed enabling legislation in 2025 to expand HST relief on new residential construction, including purpose-built rentals. The federal government already waived its 5% GST portion on qualifying rental projects in late 2023. Ontario's 8% provincial portion—the bigger share—was supposed to follow. It hasn't. The Canada Revenue Agency, which administers the program, told builders in early 2026 that it cannot process claims under the new provincial rules until Ontario files the final regulatory framework. That framework doesn't exist yet.

So builders are stuck. Projects that break ground now face the full 13% HST bill. Projects that delay risk missing the narrowing window when construction financing is still viable at current rates. The solution most are reaching for is neither cheap nor simple: temporary legal structures designed to defer the tax hit until the province catches up.

The deemed-sale trap

Here's the technical problem. Under existing tax law, when a builder completes a rental unit and the first tenant moves in, the builder is "deemed" to have sold the property to themselves at fair market value. That triggers an immediate HST payment to the CRA, calculated on the full construction cost. For a 200-unit purpose-built rental tower in Mississauga with a per-unit cost around $450,000, that's roughly $11.7 million in HST due on occupancy.

The federal rebate now covers the 5% portion. The provincial rebate was supposed to cover most or all of the 8%. Without it, builders owe the province $7.2 million they weren't planning to pay. You can't just wait it out. The tax event happens when the tenant signs the lease.

So builders are restructuring. Some are forming special-purpose entities to hold the project through occupancy, delaying the "deemed sale" moment by keeping the asset in a corporate wrapper. Others are using financing structures that treat the building as incomplete for tax purposes even after tenants move in, buying six to twelve months of runway. Both approaches cost money—legal fees, accounting complexity, financing charges on deferred payments—and both carry audit risk if the final provincial rules include retroactive provisions or anti-avoidance clauses.

One Toronto developer told Canadian Mortgage Trends in May 2026 that the corporate restructuring for a single mid-rise project cost $180,000 in legal and advisory fees, plus an estimated $400,000 in incremental financing costs to bridge the gap. That's half a million dollars spent not building housing.

The revenue-or-housing trade

The provincial hesitation isn't hard to understand. Ontario collects roughly $2 billion annually from the HST on new residential construction. Waiving 8% on purpose-built rentals—and potentially on attainable ownership units, if the lobby wins—puts a meaningful chunk of that at risk. The Ford government has argued the long-term economic return from increased supply justifies the loss. But justifying it and finalizing the regulatory math are different exercises.

Meanwhile, the gap between announcement and implementation has created a perverse incentive structure. Projects that would have started in late 2025 or early 2026 are now waiting. Developers with projects already under construction are scrambling. And the builders who can afford sophisticated tax deferral strategies are fine. The smaller operators aren't.

The attainable-ownership developers have it worse. Purpose-built rentals at least have clarity that relief is coming. Condominiums aimed at first-time buyers—units priced under $500,000—are still paying the full 13%, with no promised rebate and no workaround that doesn't involve converting the project to rental, which changes the financing, the exit strategy, and the entire pro forma.

The province says the rules are close. Close isn't operational. Until the CRA can process claims under finalized regulations, builders keep paying for fixes that wouldn't be necessary if the gap didn't exist. That's not a short-term cost. It's a tax on every unit that could have been built faster.