We built an small modular cottage for my mother-in-law next to our house (on the same lot) in 2018, and she has lived in it all of 2019. All utilities are shared with our house (electric, water, septic). She pays rent to us, we pay all utilities, property taxes, and any maintenance. Any general guidance to us? Being a new landlord we've never had to think about rental income and costs before. Since utilities are shared, should I just do a percentage based on square footage? How about real estate tax? Its all one property. Thanks for your advice.
