We reworked some of the HVAC ductwork to fit the new room layouts. This return vent was relocated to the West wall of the bedroom overlooking the loft space. We have it sealed up right now while we work on some of the drywall. I have been applying duct mastic to all the joints to prevent any air leakage in the future. We are doing this to the existing registers as well. This is not a code requirement but it will help reduce the amount of air leakage in an around the supply registers throughout the house.
We increased the size of the opening in the original loft to have more free air movement throughout the house. The whole house exhaust vent on this side of the house is located above my head in this photo. With the new opening, we will be able to exhaust the original loft through this space.