I did find the following on page 13 on the IRS publication 523.
Exceptions. The following situations apply when using
only a portion of the main home for business or rental us-
age and don’t affect your gain or loss calculations.
• Space within the living area. If the space you used
for business or rental purposes was within the living
area of the home, then your usage doesn't affect your
gain or loss calculations (except for an adjustment to
basis for depreciation, taken after May 6, 1997, to be
recaptured and reported as ordinary income). Exam-
ples of spaces within the living area include a rented
spare bedroom and attic space used as a home office.
