Radiant barrier with R38 attic insulation?? Worth it?
I'm building a home in the central California valley, where temperatures get as high as 105 in a summer day, and as low as 55 on a winter day. The house is going to have R38 insulation in the attic, but I keep going back to wondering if I should do radiant barrier in addition? The quotes I'm getting right now are about $2500, which is about $1/sq foot of attic space.
My question is... is it worth it to do radiant barrier? Our electricity is relatively cheap, about 11c / kWh. IF, and it's hard to know at all since I don't live there yet, it saves me $50 / month average during 6 summer months, that will only return $300/year, making my break even point about 8 years. I do plan to stay in the house for as much as 20. But, the $50 / month is just a wild guess.