Google: thermal insulation. I myself did thermal foil and drywall on the interior walls and rockwool in the ceilings and floors, but that's in a renovation of an old house with 15cms thick concrete single layer exterior walls. Some homework will give you more knowledge on the choices suitable for your home and climate. Ask your builder too.

Post a plan so we may understand.

Are you saying you will be layering a wooden false wall on top of the existing wall to hold the pocket door? If that is the case, you might want to treat the entire side of that new and existing wall ( including the area above doorway) as an accent wall using wood veneer strips. They look like actual pieces of wood plank which have adhesive backing, they come in a variety of finishes and colors...I like the old reclaimed wood look. A diagonal pattern would add extra visual interest, but would be more intense to cut and install. That will camouflage the additional layer and create a beautiful accent wall.

looking for some good boundary wall design for 110 ft long front boundary