The 25C credit is available for existing homes and homeowners and may receive a tax credit worth 10% of the cost of energy-efficient improvements up to $500. This tax credit expires December 31, 2013.
Homeowners that have taken advantage of this tax credit spent $7.8 billion on energy-efficient windows by 2.2 million homeowners. Energy efficient natural gas, propane, and oil powered water heaters and furnaces were second, with $5.3 billion in qualified expenditures by almost 1.4 million taxpayers. While 2.1 million taxpayers spent $3.5 billion on upgrading insulation in their homes.