Plumber has been working on stackout and we have run into some problems. We have a second story bath with double sink and the plumber ran the drain line down through the wall behind them, but it runs directly into the ac chase for the 1st floor. When questioned he said that was the only way to run it and the HVAC should work around it. Problem is that is the only ac chase, no way to work around it. If the drain can be run around a corner and then down into the floor joist system it would work. Also have an issue with waste for stackable washer and dryer. The chase will be in the way unless it is ran in the wall around two corners before going down into floor joist system. Please tell this can be done!

The stackable will be in the closet at the bottom