39 Tax Incentives Energy Policy Act of 2005 with many follow-on changes has energy efficiency incentives for existing homes. Average home loses % of its energy through inadequate insulation and inefficient lights and appliances. Energy bill offers consumers tax credits for making energy efficiency improvements in homes. For 2011: cost-based credit to for energy improvements (limit $500): 10% up to $200 for Energy Star doors & windows. 10% up to $500 for insulation, duct sealing, and infiltration reduction. 30% up to $150 for furnace or hot water boiler. 30% up to $300 for any energy-efficient heat pumps, central air conditioners, and water heaters.