We recently purchased a home that we are remodeling. The frame is 2 x 4 walls. The home has been almost completely gutted. We are looking for the best way to add insulation and increase the r value. The home is 2 stories. We removed all of the drywall and will be replacing it. The walls are insulated with rolled, faced fiberglass insulation that is in pretty good condition. However, it is only r11 on the main floor and r13 on the 2nd floor. There is no vapor barrier. There is no siding on the house right now, but it is already wrapped with Typar house wrap. Are we right in our thinking that we need to add more insulation? What would you suggest from an economic standpoint and for the least amount of headaches? Should we fur out the walls, spray foam insulation, or add foam board to the outside? It seems a shame to tear out the fiberglass insulation that is already in the walls. What do you think?