You can deduct expenses for the business use of a work space in your home, as long as you meet one of these conditions: * it 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.You can deduct a part of your maintenance costs such as heating, home insurance, electricity, and cleaning materials. You can also deduct a part of your property taxes, mortgage interest, and capital cost allowance. To calculate the part you can deduct, use a reasonable basis such as the area of the work space divided by the total area of your home.If you use part of your home for both your business and personal living, calculate how many hours in the day you use the rooms for your business, then divide that amount by 24 hours. Multiply the result by the business part of your total home expenses. This will give you the household cost you can deduct. If you run the business for only part of the week or year, reduce your claim accordingly.For more information, see Interpretation Bulletin IT-514, Work Space in Home Expenses.