“…Adding a unit to an existing residential property has the potential to make the mortgage more manageable if the costs of construction (through financing) are less than what that property owner could charge in rent. In essence, this produces a "mortgage helper" wherein the costs of owning a home are subsidized by this additional unit, therefore assisting in the repayment of the mortgage and ongoing maintenance (Mendez, 2018;Alam et al, 2021). There is research to suggest that property owners are more likely to charge below market rent when it is a known family member renting the unit (Patterson and Harris, 2017;Salvador, 2017Salvador, , 2020, with estimates from approximately 20-25% of the units being rented below market rate (Palmeri, 2014;Salvador, 2017) to up to 50% cheaper than the primary units depending on its legal status (Harris and Kinsella, 2017).…”