The profit from renting out, that is, the rental income after deducting operating expenses such as insurance, ground rent, property tax, municipal taxes, and maintenance expenses, is taxable. Correspondingly, any deficit qualifies for deductions.

Renting out commercial property when you own and live in a part of the building

As a main rule, rental income from a commercial property where you both own and live on the property is subject to tax. If you are renting out less than half of the property calculated based on the rental value, and if the property is not considered to be a multi-unit home, the rental income is not subject to tax. In sectioned buildings, the tax liability will be assessed individually for each section. 

There are separate rules for renting out your own home for a duration of less than 30 days.