BUFORD - Matthew and Suzanne Holtkamp, owners of the Holtkamp House on Maddox Road in Buford, don't consider themselves environmentalists. Rather, they call themselves stewards of God's Earth.

The Holtkamps have joined thousands of other Georgia homeowners in building an elegant new house constructed with 21st century energy-saving technology. Federal tax credits helped offset the additional costs.

The 7,500 square foot Greek Revival style Holtkamp House, built in 2006, appears to have stood on its 5.2 acres since Civil War days. It could almost pass for one of the historical homes on Madison's antebellum trail.

"I wanted an old house, but they are inefficient," Suzanne Holtkamp said. "We wanted to build a home that will last through the ages to counteract the current disposable building culture."

Money matters

Rather than buy a drafty old home that might eat up thousands of dollars in renovations, the Holtkamps researched and designed their dream home, complete with the latest energy-saving devices on the market, including a 3,000-gallon water reclamation system that saved their new plantings during this year's extreme drought.

"The builder thought we were crazy. He said, 'Why are you spending all that money? Water is so cheap,'" Suzanne Holtkamp said.

The system collects rain water from the home's gutters and pipes it underground to two 1,500-gallon storage drums.

Polysteel insulated concrete form and bricks make the home's exterior walls a tight 15 inches thick. Polysteel repels termites and can withstand 220 mph winds, Matthew Holtkamp said.

The home's attic, a space that's usually blistering hot or freezing in conventional houses, remains at a comfortable temperature due to the reflective metal roof and the foam Isynene insulation blown into the roof, rather than in the ceiling.

Its solar-powered water heater gathers energy from the sun through cells installed on the roof and supplies about 85 percent of the home's hot water, depending on the weather.

Details such as low-flush toilets, a porous driveway that minimizes runoff and the use of Energy Star appliances and windows, as well as of reclaimed architectural elements, maximize conservation.

"Based on the bills of my customers who have homes of similar size, I figure we save $600 to $700 per month on the electric bill," said Matthew Holtkamp, a heating and air contractor.

The four Holtkamps average using about 3,500 gallons of water per month since moving in last May, as opposed to the 6,000 gallons per month a family of four in a conventional home uses, according to Myron Garrett, director of Barrow County's Water Department.

"We didn't do anything extraordinary to save that amount, except to build with energy conservation in mind," Matthew Holtkamp said. "We did not change our habits."

Cost cutting

Allison Bailes, regional manager of EarthCraft House, a program created in 1999 through a partnership of the Greater Atlanta Homebuilders' Association and Southface Energy Institute, estimates a homebuilder initially spends an additional 3 to 5 percent when constructing with energy-efficient materials instead of conventional building.

"The savings are enough that they come out ahead from their first payment," Bailes said. "They save about 50 percent of their energy costs."

Three federal tax credits help offset some of that initial investment. Those credits were set to expire Dec. 31, but Congress renewed two credits through 2008, according to Teresa Croy with H&R Block in Buford.

The Holtkamp's solar water heater system cost about $5,000, including installation, he said, but a federal tax credit knocked $2,000 off that figure. Holtkamp expects to recoup his investment in three or four years, he said.

Hot water makes up about 25 percent of the average energy bill, according to Paul Prosser, owner of Solar Kitchen SE in Vienna, Ga.

The Holtkamps elected not to install solar energy panels that would manufacture their electricity. That system averages an up-front cost of about $20,000, Prosser said, adding that he sells about two solar energy systems each year. A federal tax credit would have saved the Holtkamps 30 percent of the cost of a solar energy system up to $2,000.

"It would take a while to get that cost back," Bailes said. "Solar energy has not become as mainstream as a lot of people hoped because it is cheaper to make a house more energy - efficient rather than pay for solar panels to pay for the energy wasting."

Some homeowners earn extra money from their solar energy system. If the system manufactures more energy than the family uses, the energy is returned to the local electric company through its grid and the company is required to pay the homeowner for that electricity, Prosser said.

"The most promising renewable for Georgia is biomass, burning household garbage from a landfill creates methane gas and we turn it into electricity," said Lynn Wallace, spokeswoman for Georgia Power. "We currently buy it from a landfill in DeKalb County that produces it from biomass. Customers have to pay a little extra per month for electricity produced from biomass."

A $500 tax credit for adding or upgrading insulation, air sealing or an efficient heating and air conditioning system expired Dec. 31 and was not renewed by Congress, Croy said.

Georgia offers no incentives for homeowners to add energy- efficient items to their new or existing homes, according to a spokeswoman for the Public Service Commission, but Georgia Power offers a $300 incentive to builders that construct Energy Star homes, said Wallace.

Builders also earn a $2,000 credit if they build to EarthCraft Home standards, Bailes said, adding that the organization has certified 5,000 homes in Georgia since 1999.

Join in

As the cost of conventional energy rises, more homeowners might look to unconventional manners to save, Bailes said.

"The cost of solar energy systems have been coming down and price of electricity is going up because the cost of coal and natural gas are going up," Bailes said. "North American natural gas production has peaked and it is hard to import. It must be liquefied for transport, then regasified upon arrival. It's not real safe to carry around and there's very little infrastructure in place for that type of transport."

Even existing homes can be efficiently retrofitted to conserve energy, Suzanne Holtkamp said.

"Spend some time doing your homework and consult with professionals," she said. "Research the companies and products. Start by looking at Southface on the Internet. We started our research about three or four years ago."