There were some significant changes to the energy efficiency tax credits in the stimulus bill, signed by President Obama on Feb. 17th.  This one is less of a surprise than a couple of the earlier gems we found buried in the package to move the country toward energy independence and lower cumulative greenhouse gas emissions. 

The highlights of the energy efficient home improvement provisions, according to the governments EnergyStar site, are:

• The tax credits that were previously effective for 2009, have been extended to 2010 as well
• The tax credit has been raised from 10% to 30%
• The tax credits that were for a specific dollar amount (ex $300 for a CAC), have been converted to 30% of the cost
• The maximum credit has been raised from $500 to $1500 for the two years (2009–2010). However, some improvements such as geothermal heat pumps, solar water heaters, and solar panels are not subject to the $1,500 maximum
• The $200 cap on windows has been removed

The improvements must be "placed in service" from January 1, 2009 through December 31, 2010 and must be for taxpayers principal residence.