That doesn’t sound too bad. We actually had all of the windows and exterior doors on the house replaced last year and our utility bills have been extremely low. The only part of the house that gets cold is the entry area by the garage door because of the thin door that is there. I figured if I switched that out, it would keep the downstairs a little warmer. I’ll have to go to lowes and see what type of selection they have. Did you have to widen your door frame when you switched from an interior door to a fire-rated door?