House Hacking - real costs of sharing your home

Hey folks,

I am preparing to purchase my first property and I'm looking at single family homes and renting out room(s). Learning about tax implications and I have seen that is you rent out a portion of your home you can no longer claim 100% of the mortgage interest as tax deductible. I'd like to use this post to start a discussion of how the percentage is calculated as well as other lesser known tax implications of renting out part of your home.

Thanks for your replies!