If I have roomates, do I divide the number of rooms in the house by the number of roomates I have for the purposes of business-as-home expenses?

[gode14]

For example, if I rent a house with three other people, I'm not paying to rent the entire house, just like I'm not paying the entire heating bill. When calculating what % of my heating, electricity, and rent payments I can deduct, how do I factor in the fact that I'm sharing the home with 3 others?

[TurboTax-Cristyn · Accepted solution]

You can only claim home office expenses for the portion of your principal residence that is used exclusively for the purpose of earning income from business. 

Here is some more information about claiming home office expenses:

https://turbotax.intuit.ca/tips/rules-for-home-offices-6100