Homeowner was considering adding a supply to a bedroom area for the basement. When the unit was installed in 2018, the basement was not considered actual living space, there are two supply vents going to the basement. I explained the adding a supply for a bedroom area. We would also need to add a return to prevent overheating the basement area since that area is going be closest to the furnace/AC. Since the main floor thermostat is not a zoned system. Recommended having the basement fully furnished without changing the ceiling and waiting a few weeks in the summer so we can gauge if adding ductwork is the right solution, gave homeowner ballpark estimate of $2500-$3000 to add a return and a supply for that bedroom area.