So I was trying to calculate heating requirements for my house. I was using this site for a little reference. I have R-19 walls and had R-38 ceiling. I run the numbers and I kept getting about half the BTUs. I was racking my brain and then it hit me. What about the windows and doors. You mean to tell me that I need 100% more energy just because I have windows and doors. Not to mention any air leaks. The short answer. YES!!!

Well, that is humbling. I guess when I replace the windows and doors I will look at getting the best I can buy. Also installation is key too. A great window installed incorrectly is just as efficient as a cheap window that has been installed perfectly. Weather sealing and expanding foam can make a huge difference. (IMHO anyway)