Ernie and Cathleen Butler were just hoping to get some help fixing their roof, but ended up with major home improvements that will save them money on their energy bills — all for free.

The National Association of Home Builders Research Center (search) joined the nonprofit Rebuilding Together to use the Butlers' home as a model to show how home modifications, big and small, can help keep energy costs down.

Rebuilding Together (search) is a national organization that does repair work for low-income homeowners, particularly those who are elderly or disabled. When the Research Center approached the group about finding a model home, Rebuilding Together officials knew the Butlers' would be perfect. It not only needed a new roof, but it had leaky windows, drafty doors and no insulation.

"It was hard to get our house warm ... our bills were high," said Cathleen Butler, 64. Since her husband, 59, uses a wheelchair, she said, she had to climb on the roof during last year's storms to push snow off, afraid the roof would cave in.

Volunteers replaced the roof and installed insulation, new siding, doors and windows. They also tackled smaller jobs, including using compact fluorescent light bulbs. Other work was done to make rooms more wheelchair-accessible. Supplies were donated by area businesses.

The Butlers could save 40 or 50 percent on their energy bills because of all the major repairs, the Research Center said.

But even smaller jobs can save homeowners money.

Low-income homeowners can spend almost 20 percent of their income on energy bills, and elderly owners on fixed incomes can spend up to 35 percent, according to a 2001 study from the National Low-Income Energy Coalition (search).

For the elderly and disabled, the high costs sometimes mean choosing between a warm home and buying food or medicine, said Lottie Gatewood, spokesperson for Rebuilding Together.

"This is particularly important now, when energy costs are skyrocketing," Gatewood said.

The U.S. Department of Energy (search), which funded part of the project, reported in early October that prices could rise 9 percent for natural gas and 3 percent for electricity.

The Energy Department has also included in the project a checklist of ways to make a house more energy efficient.

The checklist details smaller measures, like caulking, weather-stripping, sealing ductwork and using energy-efficient light bulbs, that can save homeowners up to 20 percent on their annual bills, according to Gatewood.

The project combines the technology and energy savvy of the Research Center with Rebuilding Together's know-how and experience with low-income homes.

"The project is a nice extension of our research," said Michael Luzier, president of the Research Center, which focuses on housing technology, affordability and energy efficiency. "A project like this combines those."

Rebuilding Together has never focused on energy efficiency, said Pat Pyles, vice president of the chapter at Anne Arundel, Md., near the Butlers' home.

"Our motto is 'warm, safe and dry,' and now we can lower their energy bills too," said Maury Chaput, president of Rebuilding Together, Anne Arundel County.

Capital News Service contributed to this report.