My parents did this when they started their software company in the early 80s. It only happened because a group of their friends was starting a bank -- they go

My parents did this when they started their software company in the early 80s. It only happened because a group of their friends was starting a bank -- they got a sweetheart deal that included a mortgage for the neighboring apartments in the co-op they lived and worked in (later combined into one 1700 sqft apartment). My mother worked out a sweet tax deal where the business paid them rent on the office portion of the apartment, including the 'executive washroom' (complete with kiddie pool). At some point in the 90s the bank got merged and acquired a dizzying number of times. I'm pretty sure the business loans got paid off before that, but the sweetheart mortgage remained.