If you don't find what you need I have my hand calculations for heat gain in the summer and loss in the winter that I could e-mail you. Once you have the area for your attic, walls and windows it is pretty straight forward. I also have a detailed work sheet that the power company used to provide. I did this back in the first energy crisis around 1976 as a fun engineering project. Based on the calculations, we added more insulation in the attic, installed storm windows and added 2 in. duct insulation over the original 1 in.
