Home Office CCA and the Principal Residence Trap

You are self-employed and you work from a room in your own house. Every spring, you deduct part of the heating, the electricity, the insurance. The form also offers to deduct part of the house itself, through capital cost allowance (CCA). It is the one line on the list you are almost always better off leaving empty: it can cost you, on the day you sell, the most valuable tax break a household has.

What a home office lets you deduct

A self-employed person who uses part of their home for the business deducts part of their household expenses. The CRA lists them on its page about business-use-of-home expenses: part of your maintenance costs such as heating, home insurance, electricity and cleaning materials, but also part of your property taxes, your mortgage interest — and CCA.

These expenses go on line 9945 of Form T2125, the business income form. One limit applies: the amount you deduct cannot be more than your net income from the business before you deduct these expenses. So they can bring your profit down to zero, not turn it negative.

The two ways in

You still have to qualify. The CRA sets out two situations, and one of them is enough:

• the space is your principal place of business;
• or you use the space only to earn your business income, and you use it on a regular and ongoing basis to meet your clients, customers or patients.

The kitchen table where you answer emails in the evening meets neither one.

CCA: the one box not to tick

CCA is the deduction that spreads the cost of a long-lasting asset over several years instead of deducting it all at once. If the mechanism is new to you, start with our introduction to CCA; what follows assumes you have it.

Applied to a house, CCA runs through the CRA's classes of depreciable property. Most buildings acquired after 1987 belong to Class 1, and the rate there is 4% a year. And one detail changes the order of magnitude: land is not depreciable property. Only the part of the price that belongs to the building counts.

A round-number illustration, just to fix ideas — this is not your case. An office takes up 10% of a house whose building portion cost $300,000. The depreciable share of the office is therefore $30,000, and 4% of that amount comes to $1,200 of deduction for one year.

What is that deduction worth? It lowers your taxable income, so it saves you your marginal rate — the percentage of tax that hits your last dollar earned, not the average across all of your income. In Quebec, on a taxable income of around $60,000, our calculator puts that rate near 36%. So the $1,200 is worth roughly $430 less tax for the year.

The principal residence exemption, in plain words

When you sell an asset, the increase in value — the difference between the sale price and what the asset cost you — is a capital gain, and a capital gain is taxable. Your home is the exception. The CRA says so on its principal residence page: if the home was solely your principal residence for every year you owned it, you do not have to pay tax on the gain.

It is an exception that shelters the whole increase in value, however large. For a year to count, the property has to meet four conditions: it is a housing unit (or a leasehold interest in one, or a share of the capital stock of a co-operative housing corporation); you own it, alone or jointly with another person; you, your current or former spouse or common-law partner, or any of your children lived in it at some time during the year; and you designate it as your principal residence.

The CRA's three conditions

An office inside the house is a business use. In principle, that use changes the use of that part of the home, which would take it out of the shelter. In practice, the CRA does not apply that as long as three conditions are met. The Capital Gains guide lists them:

1. the income producing use is ancillary to the main use of the property as a residence;
2. there is no structural change to the property;
3. no capital cost allowance is claimed on the property.

The first two you meet without thinking about them: one room among others, no walls knocked down. The third one is up to you alone, every year, when you fill in a box.

What happens on the day you sell

The CRA is explicit on its business-use-of-home page: the capital gain and recapture rules will apply if you deduct CCA on the business-use part of your home and you later sell your home.

So two bills arrive together, and they are different in nature.

Recapture. The deductions you took over the years come back into your income, all at once, in the year of the sale. It is not a penalty: it is a deduction taken back. Our article on recapture and terminal loss works through the calculation.

The capital gain. The part of the house you claimed CCA on is no longer covered by the exemption. The increase in value that belongs to it becomes taxable, while the increase on the rest of the house is not.

The same rule turns up elsewhere. The principal residence page notes that if you turn your home into a rental property, the election that lets you defer reporting the gain is open to you only if you have not claimed CCA on the property. A box ticked today closes doors you often do not know exist.

What to take away

• Deduct everything else. Heating, electricity, insurance, cleaning materials, property taxes, mortgage interest: the share that matches your office is deducted on line 9945, and none of it touches your principal residence.
• Leave CCA alone. Our article on the years when claiming nothing is the better move counts double here: on a house, this year's gain does not weigh much against what it puts at risk.
• Keep a record of the percentage your office takes up and of how you arrived at it. That is what backs up all your other deductions.
• If you have already claimed CCA, do not improvise: that situation gets sorted out with an accountant who has your file in front of them.
• These rules are federal. In Quebec you also file a provincial return; check the Quebec treatment with Revenu Québec.

This article explains a general mechanism; it does not replace advice from a professional who knows your situation.