I build an in-law unit in my property, attached to my original house with complete permit to help brother to have a place to live. Put him on a lease for my protection and has expired a long time ago. He pays same price as the room he previously rents but with kitchen & private bath and 1 bedroom that's why it's only 51% FMV. Never claimed in my tax any of construction cost and any cost related to his additional expense renting. But recently, my coworker mentioned his similar case, he said still need to be reported. Should I amend the 2016? and how do I add the construction cost? Not really interested in any deduction if it will complicate my tax. Thanks.
