The American Taxpayer Relief Act of 2012 retroactively renewed this tax credit effective January 1, 2012, expiring again on December 31, 2013. Any qualified equipment installed in 2012 or 2013 is eligible for this credit. As in previous years, the cumulative maximum amount of tax credit that can be claimed by a taxpayer in all years combined is $500. If a taxpayer has already claimed a tax credit of $500 for purchases made in any previous year, they are ineligible for additional tax credits for any new equipment purchases.

This credit applies to energy efficiency improvements in the building envelope of existing homes and for the purchase of high-efficiency heating, cooling and water-heating equipment. Efficiency improvements or equipment must serve a dwelling in the United States that is owned and used by the taxpayer as a primary residence. The maximum tax credit for all improvements made in 2011, 2012, and 2013 is $500. The cap includes tax credits for any improvements made in any previous year. If a taxpayer claimed $500 or more of these tax credits in any previous year, any purchases made in 2011, 2012, or 2013 will be ineligible for a tax credit.

Building Envelope Improvements
Owners of existing homes may receive a tax credit worth 10% of the cost of upgrading the efficiency of the building's envelope. Installation (labor) costs are not included and the credit is capped at $500 for all improvements. To be eligible for the credit, the improvement must meet the prescriptive requirements established for it under the 2009 International Energy Conservation Code (including supplements). The following improvements are eligible for the tax credit:

Insulation materials and systems designed to reduce a home's heat loss or gain
Exterior doors and windows (including skylights) --- no more than $200 in total credits can be claimed for windows in years 2006 - 2013
Pigmented metal roofs designed to reduce heat gain, and asphalt roofs with appropriate cooling granules.

Heating, Cooling and Water-Heating Equipment
Taxpayers who purchase qualified residential energy-efficient property may eligible for a tax credit. The credit is equal to the full cost of the equipment up to the following caps:

Advanced main air circulating fan: $50
Natural gas, propane, or oil furnace or hot water boiler with an annual fuel utilization rate of 95 or greater: $150
Electric heat pump water heater with an energy factor of at least 2.0: $300
Electric heat pump which achieves the highest efficiency tier established by the Consortium for Energy Efficiency: $300
Central air conditioner which achieves the highest efficiency tier established by the Consortium for Energy Efficiency: $300
Natural gas, propane, or oil water heater which has either an energy factor of at least 0.82 or a thermal efficiency of at least 90 percent: $300
Biomass stoves that use "plant-derived fuel available on a renewable or recurring basis, including agricultural crops and trees, wood and wood waste and residues (including wood pellets), plants (including aquatic plants), grasses, residues, and fibers": $300