Congress passed an energy bill last year that includes several tax credits for home improvements that are energy saving. The credits are limited to eligible improvements made between December 31, 2005 and January 1, 2008. One of the credits is 10% of the cost of eligible improvements up to a cap of $500. The credits are limited to your primary home. Tax credits are more valuable than deductions because credits represent a dollar-for-dollar reduction in your tax bill.