Oct. 9--Energy prices are up, but take heart. A new law offers homeowners a 10 percent tax credit for many costs related to improving energy efficiency.

This applies as long as the addition or improvement meets the federal energy-efficiency standard.

So if you install an energy-efficient pigmented metal roof, you may turn in the receipt to the government and get back 10 percent of your investment.

The tax credit also applies to water heaters, heat pumps, furnaces, boilers, windows, skylights and exterior doors. It is also good for house-enveloping strategies, such as insulation and duct sealing.

Overwhelmed by where to begin? It's a good idea to start with insulation, said Wilson Gonzalez, a senior regulatory analyst for the Ohio Consumers' Counsel.

Homeowners also should consider replacing a furnace that was made before 1992, which is when energy standards were increased, Gonzalez said. Old furnaces are about 60 percent efficient, compared to 90 percent to 95 percent with new appliances. The energy bill provides a tax credit of up to $300 for a new furnace.

For the most part, people with older homes have the most to improve. However, owners of new homes can invest between $30 and $100 for a set-back thermostat, which will program a temperature for certain times each day.

If you aren't sure how efficient your home is, a professional energy audit is a good idea, Gonzalez said. It will cost about $400.

To be eligible for tax credits, consumers must pay for the efficiency upgrades between Jan. 1, 2006, and Dec. 31, 2007. The total tax credit is limited to $500 during the two-year span.