Running a business from home: what it does to the principal residence exemption

For most Canadian business owners, the family home is the largest tax-sheltered asset they will own. Does working from it put that shelter at risk? Usually not, provided three conditions hold, and one of them is a deduction many owners claim without thinking.

What the principal residence exemption actually is

A home that was your principal residence every year you owned it generally sells tax-free. It qualifies for a year if it is a housing unit (house, condo, apartment, cottage, mobile home or houseboat) you own, you, your spouse or common-law partner, or a child lived in it that year, and you designate it. For a rental-only property, see selling a rental property.

Two limits apply: one property per family per year for 1982 and later, and generally half a hectare (1.24 acres) of land, unless more was needed for the home, such as a larger municipal minimum lot size.

Even where the whole gain is exempt, the sale must still be reported: on Schedule 3 and Form T2091(IND) for the year of disposition.

The three conditions that protect the exemption

Using part of your home for rental or business is usually a partial change in use, with a deemed disposition of that part. It does not apply if all three of these are true:

• the rental or business use of the property is relatively small about its use as your principal residence;
• you make no structural changes to the property to make it more suitable for rental or business purposes; and
• you deduct no capital cost allowance on the part used for rental or business.

Meet all three and an ordinary home office is a non-event for the exemption. Fail any one and there is generally a deemed disposition of the affected portion at its proportionate share of fair market value.

The CCA trap

Of the three, capital cost allowance is the trap. The building is depreciable and software will calculate the claim, but the modest deduction makes the business portion taxable on all future appreciation.

On a long-held home, that trade rarely pays, so claim operating costs only, as our guides to the home office deduction for incorporated owners and home office expenses advise. Designate on form T2091(IND). See why every sale has had to be reported since 2016, even when no tax is owed.

Since 2019, an election is available

Before 19 March 2019 there was no election out of the deemed disposition on a partial change in use. Since then, depending on the circumstances, an election under subsection 45(2) or 45(3) can prevent it. Where a deemed disposition does occur, you can still designate the affected portion for the year of the change by completing Part 2 of Schedule 3 and page 2 of Form T2091(IND). Our guide to change in use rules sets out both elections.

What happens on the eventual sale

If a portion of the home did change use, the sale is handled in parts:

• Split the selling price between the principal residence part and the rental or business part. The CRA will accept a split based on square metres or number of rooms, provided it is reasonable.
• Report the capital gain on the rental or business portion.
• Claim the principal residence exemption on the portion that never changed use, via Schedule 3 and Form T2091(IND). No gain is reported on that part.

Record floor areas, the dates the use changed, and fair market value at each change. Keep these with your permanent tax records, not the year’s receipts.

Renting part of the home is the higher-risk version

A basement suite is a bigger use than a home office, often with structural changes and a tempting CCA claim, so the three conditions are easier to fail. If you rent part of your home, analyse the change in use properly and split expenses reasonably before claiming.

The bottom line

A home office rarely costs you the exemption. Keep business use modest, make no structural changes for it, and claim no CCA on the building. For larger uses or a suite, confirm the position before claiming. An accountant in Abbotsford can settle it in one conversation.

This article is general information for Canadian business owners and is current as of July 2026. It is not tax, legal or accounting advice, and your situation is unique, so please speak with a CPA before acting on anything here.

Working through this locally? We advise owners on it as an accountant in Abbotsford.