(If this has been posted and I missed it, I apologize.) It was reported here that the American Recovery and Reinvestment Act of ’09, though it was appreciated, unfairly limited the SHGC for windows in northern climates (“limited”, if you wanted to get a tax break). That was true, though the situation has apparently been corrected for 2011. I just got this from my US Representative. ” For 2011, the SHGC standard was set to the ENERGY STAR criteria for our climate zone. http://www.energystar.gov/index.cfm?c=windows_doors.pr_anat_window

The tax credit for improvements installed in 2011:
• 10% of purchase price (not including installation cost)
• Maximum credit: $200 for windows and skylights, $500 for doors (overall credit limit for qualified energy-efficiency improvements: $500)”

It is encouraging to see that “those people in Washington” may actually listen to “the rest of us”.