1800's old House total remodel. Third floor attic is all new spray foamed roof, soffit , walls. NO ROOF VENTS at all now.
Large staircase leading to this attic space. There will be a horizontal 95% gas furnace and ac system up there.
Does duct need to be insulated ? The ceilings below will not be insulated just drywall.
The staircase door leading to this area will be undercut. Builder wants a return in attic duct to draw air from under cut door up into attic for air change.