I've been thinking about this a lot. I know people who, because of the housing market, have created a flat inside their house that they rent out to help to cover the insane mortgage payments.

I see this as, yes, they are using other people's money to help to buy the house for themselves, however, if someone richer had bought the house that flat probably wouldn't exist. Also, it's not their living, they also have jobs.

Anyway, I consider that a different category than having a strong of rental units that provide an entire income.