Although both types of employees (salaried & commission) claiming Employment Expenses are eligible to claim "Rent" as a Work-Space-In-Home expense, there are different rules for home owners.

• Mortgage Payments - The actual mortgage payment is never allowed as a tax deduction, only interest paid on the mortgage. However, as an Employment Expense, CRA does not permit either type of employee to claim their mortgage interest.
• Property Tax - Property Taxes can only be claimed by employees who earn "Commission Income".

Please see the following CRA Guide for a complete list of eligible and ineligible expenses: https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/t4044/employment-ex...