I have a 6 year old home with about 12 inches (R-30) of blown-in insulation in the attic. Recently door-to-door sales representatives for an insulation company offered a free inspection and quote to add additional insulation. The pitch was that the R-value at the time of construction was sufficient, but that codes have been revised and more insulation is better.
I was provided with options for adding 8 or 12 more inches to attain R-49 or R-60 respectively.
Sure, insulation materials improve with technology, but should I agree to have additional insulation put in? Will adding more somehow pay for itself? Is there such a thing as too much?
I live in a desert climate with temperatures ranging from -20°C (-5°F) in winter to 32°C (90°F) in summer.