Hello,

here's my situation: I live in a house and rent rooms on AirBnB. What can I deduct?

1) I live in 1/2 of the house (sqft). However it is only 1 bedroom: I rent 3 bedrooms on AirBnB. My research told me to split common bills on tax return either per sqft or per bedroom. Do I get to chose? (If yes, the bedroom split is much more in my favor). Bills I can think of in this category: Mortgage Interest, Insurance, Utilities, ...

2) I have consumable expenses (Shampoo, Towels, Sheets, ...). I believe I can deduct these, or am I mistaken?

3) What about other expenses such as furnitures, electronics, wall insulation, plumbing in the rented space? Does it fall into the 100% deductible (as in not divided per sqft/bedroom), amortized over X years category?

4) What about expenses such as retro-fitting the place to get it airbnb-ready (I had to add doors, buy keypad locks, smart thermostats, ...)

5) I do a lot of the work myself. Instead of having a contractor bill, I have receipts from the hardware store. Are tools & parts deductible?

6) Are there common deductions I am forgetting about? Not trying to be greedy, just getting a quick understanding of commonly deducted expenses that are often overseen.
Thinking of maybe: cell phone bill, home office space, gas used (this one is a stretch since I live on the property).

I am in California (not sure if that matters).

Thank you!