I have a rental income suite in my home. I am also newly self-employed and work from home. Do I enter my home expenses under one or the other, or both?

The rental suite is 30% of the home, and I have claimed this income and deductions in previous years.  
My home office is 20% of the home.  I claimed this using the flat rate method while I was employed elsewhere.  Now that I am self-employed, can I use the detailed method?  Can I claim the home expenses in both places, or just one?