The image below is from a recent inspection I did of a brand new home in which the attic access door was not insulated. An uninsulated door like this is one of the most common things I see during inspections! The "hole" this creates in the thermal envelope of a house is huge! Would you leave your window open all year when your heat and AC is on? Think of this in the same way.
Imagine opening up the smallest window in hour home on the coldest day of the year. I could say, "That window only accounts for less than 5% of your total wall, so don't worry, you won't loose that much heat." Would you believe me? Of course not! We all know how fast the inside of our home will cool down if we even crack a window!
Our attic access's have the same effect. Although they may account for only 5% or less of our ceiling space, leaving this uninsulated can make your tightly sealed attic your homes greatest energy loss. The good news, it's extremely easy and cheap to remedy! A couple of layers of rigid foam insulation cost's less than $20 and won't effect your ease of access. Check your's today and start saving money on your utility bills!