Building a House to Sell: Builder Tax Rules
Building a house to sell: business income vs capital gain, HST as a builder, the 365-day flipping rule and a worked Ontario spec-house example.
The short version
- Build a house with the intention of selling it, and the profit is usually business income: fully taxable, no principal residence exemption, and no 50% capital gains break.
- For GST/HST you're a builder: HST is charged on the sale price of a new home, and you claim input tax credits on what you paid if you're registered. In Ontario that's 13%.
- Live in it first as your real home, and the sale can be exempt from HST and the gain tax-free. But move in for show, and CRA looks at your intention, and the 365-day flipping rule.
- Profit from a sale within 365 days of buying a home is treated as business income under the flipping rule, with exceptions for life events like a death, separation or job move.
- In Ontario, building homes for sale needs a builder licence from the Home Construction Regulatory Authority and Tarion warranty enrolment, with exceptions for owner-builders.
Building a House to Sell: Builder Tax Rules
Every tradesperson who has built a few houses has done the math: buy a lot, build a house with my own crew at cost, sell it at market, keep the difference. The math is right. The tax on it is the part people do on a napkin and regret on paper. A house built to sell is inventory, not a home; the profit is income, the sale carries HST, and the paperwork looks a lot like a small developer's. Here's how it works, before the foundation is poured.
Business Income or Capital Gain?
| Facts that point to business income | Facts that point to capital or exempt |
|---|---|
| You built or bought to sell, or listed it before or soon after completion | You built it as your home, moved in and lived there for years |
| You're in construction or real estate | No construction or real estate business |
| You've done it before | A one-time event |
| Financing was short-term, construction only | A normal residential mortgage |
| Sold within 365 days of buying (flipping rule) | A life event caused an early sale |
More on the line between them: house flipping and vacant land.
Planning to build and sell?
Tell the assistant the lot cost, build budget, expected sale price, province and whether you'll live in it. It estimates income tax and HST and shows how the answer changes if it becomes your home first.
Example: One Spec House in Ontario
| Amount | |
|---|---|
| Lot | $200,000 |
| Construction (net of HST input tax credits) | $550,000 |
| Sale price before HST | $950,000 |
| Profit before tax | $200,000, fully taxable as business income |
| HST collected on the sale, before buyer rebates | $123,500, remitted to CRA |
The profit is added to your income for the year and taxed at your marginal rate, with CPP on top if you're a sole proprietor. A corporation can lower the tax now; see corporation vs sole proprietor. New-home HST rebates go to the buyer and are often credited by the builder; see GST/HST new housing rebate and, for Ontario, OntarioHSTRebates.ca.
HST for the Builder
- Register for GST/HST before you start; sales of new homes are taxable even for a one-off builder. See how to register.
- Claim input tax credits on materials, subs and services, with proper invoices; see input tax credits.
- Charge HST on the sale and remit it, net of ITCs.
- Rent it out instead? The self-supply rule applies: HST on its value when the first tenant moves in. See garden suites and rental units.
- Building for yourself? Different rules and rebates; see owner-built home rebate.
Building to sell and need your HST set up right?
The GST/HST SmartFile works out your registration, what to charge on the sale, the input tax credits on your build costs, and the rebate credited to the buyer.
Mistakes Builders Make
- Calling a spec house "my home" after living in it a few months. CRA looks at intention and history, and the flipping rule backs it up.
- Not registering for HST because "I'm not a builder." Selling a new house makes you one.
- Missing invoices for subs, which kills input tax credits; see paying subcontractors.
- Forgetting licensing and warranty rules in Ontario until the buyer's lawyer asks.
Building to Sell Questions
Is profit from building and selling a house taxable in Canada?
Yes. If you built it with the intention of selling, the profit is usually business income, fully taxable. The principal residence exemption and the 50% capital gains inclusion do not apply.
Do I charge HST when I sell a house I built?
Generally yes. A sale of a newly built home is taxable, and the builder charges GST/HST and can claim input tax credits on construction costs. An exception exists for a builder who built the home for personal use and lived in it as their primary place of residence.
What is the 365-day flipping rule?
Profit from selling a home owned for less than 365 consecutive days is treated as business income, unless the sale was due to a listed life event such as a death, separation, disability, new job or a new child.
Can I avoid tax by living in the house before selling?
Only if it truly becomes your home and you did not build it to sell. CRA looks at your intention, history and the facts; a short stay usually does not change a spec build into a principal residence.
Should I build through a corporation?
A corporation can lower the immediate tax on builder profits and separate the risk, but adds costs. Compare the options before you start.
Sources: CRA, RC4028, GST/HST New Housing Rebate; Folio S1-F3-C2, Principal Residence. Checked October 2026. Whether a sale is business income depends on the facts. The personal-use exemption from HST has strict conditions. Ontario licensing and warranty rules are summarized only; check with the Home Construction Regulatory Authority and Tarion. The example is illustrative and ignores financing and selling costs.
Last reviewed October 5, 2026 against CRA and Government of Canada sources. How we check our facts.