I recently bought a 120 year old 2200 square foot house in the snow belt of Western New York. After my purchase I proceeded to gutt the whole house with exception to the second floor ceilings (which still contain blown in cellulose - I wish I could have kept going, but I know anyone that has gutted a house that contains blown in insulation and lath and plaster understands why I stopped.....). Since the house walls are made of 2x4 construction I am looking for the best insulating solution as our winters our definately cold, blowy and snowy. I have researched foamed insulation, but am not completely sold as it is 3x the cost of traditional batt insulation. I understand the upside is that I would be able to achieve a R value of 21 (rather than 14) with just 3 inches of the foam, but is the cost recoupable if I only plan on living there for only a couple of years? Is there a formula I can use to figure out how much money is saved per R value? I was also wondering if I insulted with Batt insulation on the inside and only acheived an R value of 14 would it be cost effective when I resided the house to use on the outside 1 inch of foam board to achieve an R value of 18? I keep going back and forth on what I should do monetarily wise.... I just installed a brand new gas boiler base board heating system and with such high heating costs I would hate to spend more money than I have to keeping the place warm. If anyone could please advise it would be greatly appreciated.

I am considering the purchase of an older house. I am concerned about the attic insulation. It has the usual layer of rolled fiberglass insulation, but also has an additional 2 or 3 inches of blown-in beads of white foam. I am under the impression that this could pose a hazard in the event of a fire. One insulation contractor said that this is not a problem, another contractor confirmed my worst fears and said this stuff neads to be removed. He also said this product is only approved for use of insulating cores of cement blocks Who's right? Thanks for your help.