When you have a house that is part personal residence, and part rental property some parts of the tax code become complex. You will have to divide all the expenses (mortgage, property tax, insurance) and split it between the two uses. You will also have to take that rental portion of the property and depreciation it. You will need to determine the value of the property before the split and then determine the value of the rental portion at the time of the split. From then on, you will follow the IRS regulations for depreciation of the rental portion until you either convert it back to non-rental or sell the property.
When the property is sold the portion of the sales price will be associated with the rental property, and you will need to determine if the rental property is sold for a profit or a loss. You will also have to recapture the depreciation. It is possible that one portion of the property could show a loss, and the other part of the property a gain depending on house prices over the decades.
You can expect that AirBnB will collect tax info and send it to the IRS
since it seems you're saying a portion will not be used as your personal residence it won't qualify for the home sale exclusion unless you stop renting and make it part of your principal residence. Then special rules apply to the home sale exclusion on this part of your home.
since tax rules change over time, consult a tax pro as far in advance of any sale as soon as possible.
also, consult with your insurance agent before starting the rental. it is possible you may need an insurance rider to cover the BNB part.
