@fanfare - here is the link for the simplified method from the IRS
https://www.irs.gov/businesses/small-businesses-self-employed/simplified-option-for-home-office-dedu...
one of the requirements is that
"Deduction for home office use of a portion of a residence allowed only if that portion is exclusively used on a regular basis for business purposes"
the room is not used exclusively for his home office; it doubles as @Jusdreiin's bedroom and therefore he cannot use the simplified method. Therefore, the only expenses he can deduct are his actual expenses.
best,
