Tom, I have a 1960's vintage brick veneer ranch one story with 2x4 wall construction and drywall. My wife does not want a contractor drilling holes from the inside to insulate the outer wall. In the wnter the walls are very cold. There is no wall insulation at all. Is there a insulation method from the outside that would work and pay off in heating savings. The house is knob and tube wired and is heated with force air via natural gas. Size is 1800 square feet and the overall outside length totals 190 linear feet. If so, how long would the payoff take around.