GREEN BY THE NUMBERS

According to a U. S. Green Building Council Study, a LEED-certified home costs about 2 to 5 percent more to build than a conventional home. Here are some of the estimated costs of popular green features and expected savings over time.

Feature: Geothermal heating and cooling system.

Additional upfront cost: 33 percent more than a conventional home for the entire heating, ventilating and air conditioning system.

Annual savings: 50 to 65 percent on utility bills.

Payback: 6 to 8 years.

Feature: Photovoltaic solar panels that generate electricity.

Additional upfront cost: $9,000 after rebates and grants.

Payback: 22 years.

Feature: LED recessed can light.

Additional upfront cost: $50 to $70 before rebates.

Savings: $400 over life of bulb, which is 20 years.

Payback: 5 to 8 years.

Additional upfront cost: None.

Annual savings: 33 to 67 percent, depending on your water usage.

Payback: Immediate.

LYNN UNDERWOOD

• Determine your goals. Do you want to lower utility bills, reduce your carbon footprint or live in a healthy home? This will help you prioritize your decisions and budget.

• Calculate incremental costs and benefits to determine if you will get a payback over the lifetime of the product.