Selling an Owner-Occupied Plex in Quebec: The Principal Residence Exemption, Unit by Unit

You live in one unit of your duplex or triplex, and you are selling it. The capital gain on an owner-occupied plex does not have a single tax status: one part belongs to the unit you live in, another to the units you rent out. This article sits at the moment of sale and follows the calculation, unit by unit. The general rules of the exemption, including the designation and the "plus one year" rule, are covered in our article on the principal residence exemption.

An owner-occupied plex sells as two tax properties

The principal residence exemption shelters the gain on the unit you ordinarily live in. It does not extend to units rented to others, which are held to earn income.

When you sell a plex you live in, you are selling, in one transaction, two things that tax treats differently: a residence, whose gain can be exempt, and a rental property, whose gain is taxable. The work of the calculation is to separate the two.

Allocating the price and the cost between units

The split is made on a reasonable basis, for example the floor area of each unit. In a triplex of three units of equal size, your unit represents one third of the building; in a duplex where the upper unit is twice the size of the lower one, the proportion is no longer half.

The same proportion applies to every element of the calculation: the sale price, the purchase cost, selling costs and shared capital expenses such as a roof or a foundation. An improvement made in a single unit, such as a renovated kitchen, belongs to that unit only. The result is two separate gains, one for the part you live in and one for the rented part.

Your own unit: the formula, applied to that unit only

The gain on the part you live in is exempt in the following proportion: the number of years that unit was designated as your principal residence, plus one, divided by the number of years you owned the property. If you lived in the same unit for the whole period, and no other property in your family unit was designated for those years, the ratio reaches or exceeds one: the gain on your unit is fully exempt.

The formula never applies to the gain on the rented units. Designating the plex as your principal residence does not bring the rented part into the exemption: the designation only covers what you live in.

The sale is reported in the year it takes place, even when your unit is fully exempt, with the principal residence designation filed at both levels of government.

The rented part: a taxable gain, and depreciation coming back

The gain on the rented part is an ordinary capital gain. Half of that gain is added to your taxable income.

If you claimed capital cost allowance on the rented part over the years, the sale can bring some of it back into your income, on top of the gain. That mechanism is detailed in our article on selling a plex and tax optimization. For the calculation here, keep in mind that it applies to the rented part only.

A constructed example: a triplex, one unit occupied

The figures below are a constructed example to isolate the mechanism, not a real sale. They ignore selling costs and improvements.

• A triplex with three units of equal floor area, bought for $450,000 and sold for $840,000 thirteen calendar years later.
• Total gain: $390,000, or $130,000 per unit.
• The seller lived in the same unit for the whole period and designated it for all thirteen years.
• Owner's unit: $130,000 of gain, ratio of (13 + 1) over 13, so fully exempt.
• Rented part: $260,000 of capital gain, half of which is added to income, plus any recaptured depreciation.

In this example, the seller paid for the whole building, but only one third of the gain escapes tax. That is the number to know before working out what the sale will leave you with.

When occupancy changed during ownership

The calculation gets harder as soon as occupancy has shifted: you left your unit and rented it out, you moved from the ground floor upstairs, or you combined two units into one. Each change of that kind alters the use of part of the building.

A change in use can be treated as if the part concerned had been sold at its value at the time, with a tax effect that same year. Elections exist to defer that effect in some cases, but they must be made within strict deadlines, which differ by election, and depend in particular on the depreciation claimed. Discovering the issue at the time of sale means risking finding out too late to make those elections.

For the seller, the practical consequence is about records: you need to be able to say, unit by unit and year by year, who lived there. That timeline determines which years can be designated for the unit you lived in.

What to gather before listing

• The purchase price and date, and the acquisition costs.
• The floor area of each unit, or whatever allocation basis you have used in your returns so far.
• The occupancy timeline, unit by unit.
• The capital cost allowance claimed on the rented part, year by year.
• Improvement invoices, separating shared work from work in a single unit.
• Any tax elections already filed, if there was a change in use.

With these documents, a tax professional can put a number on the taxable share before the property is even listed. That is when the number is useful: it changes the net proceeds of the sale, and therefore the price below which selling no longer makes sense for you.