I have an 800 sq ft house I've fixed to sell. It's being rented now. Problem is heating costs. New wall funace, New ceiling dry walled. Walls are still Paneling over studs. House on slab. Everything in the bathroom froze at times last winter. Before that (summer 14) I had put heating tape on hot and cold from source to water heads. Also had a small Eden Pure and small in wall electric heater running. Bath is only 6x8.
Since i have the inside finished I thought maybe blown in insulation but I've read good and bad thins, also with the interior walls panel they won't take much pressure. Some one told me they had a similar bath and they dug down four feet around its perimeter and placed sheets of insulation Styrofoam vertical and it solved their problem.
What about removing the siding, building a "false' insulated stud wall next to the sheathing then finish it off with sheathing and siding.
Windows do have storm windows but many yrs old.
I know I should have removed the paneling and dry walled. Big Oops !