All, I would appreciate it very much if insight could be offered on the questions below. I will also ask an accountant but want to hear a variety of opinions first. Suppose one buys a duplex that has two sides that are 1/3 and 2/3 of the total size. Option A: Live in duplex as primary residence (1/3 side) - Repairs made on rental size would be tax deductible. - 2/3 of general house renovations (e.g., roof) would be tax deductible. - 1/3 of mortgage interest would be tax deductible (?) - If one's income is over 150K, deductions on renovations can't be claimed until sale of house. Option B: Have primary residence elsewhere - all repairs on duplex are tax deductible - no mortgage interest on duplex is deductible (?) Assumptions: - house price 315k, renovations 60k, mortgage interest 1k/month, purchased w/ 4 months left in tax year. My hunch is that it would be beneficial to claim primary residence elsewhere, do all 60k in renovations during remainder of current tax year. Pro: full 60k in future deductions, and increased rent. Con: lose 4k in mortgage interest deduction, 4 month cost of primary residence elsewhere (assume minimal), and need to document that primary residence is elsewhere. If one then moves back into duplex in subsequent tax year, does this negate the full 60k deduction? Are there other angles I am missing? Thanks!!