The old, generous credits offered by the 2009-2010 American Recovery and Reinvestment Act (ARRA) – were allowed to expire and were not renewed. The current tax credits are only 10% of your total remodeling investment up to a maximum of $500. The prior cap in 2010 was $1500. Anyone that took advantage of the prior tax credits cannot utilize the credit in 2011 (no double-dipping). This means that anyone wishing to upgrade energy related products like insulation or replacement windows as part of their remodeling project in 2011 can expect to receive only a maximum tax credit of $500 on an investment of $5000. see: http://www.energystar.gov/index.cfm?c=windows_doors.pr_taxcredits
