Hello, I have a question about attic insulation.. I'm building a house in northern NJ. It's a two story colonial house. I have two options in terms of insulation - insulate the attic roof (I was considering 3' spray foam + R15 fiberglass) and not do anything on the ceiling of the 2nd floor OR insulate 2nd floor ceiling (with R36 fiberglass) and not do anything in the attic. I know that insulating the roof would be more costly, but i'm building the house for myself, I expect to be living there for...