The word that best explains the new house on Beacon Hill Lane in Creve Coeur is special.

And the superlative extends beyond four bedrooms, 5,000 square feet, 1-acre lot and $1.2 million price tag.

What really sets the house apart is its energy use, or lack thereof.

With construction almost complete, St. Louis-based Sage Homebuilders has thrown just about every energy-efficient trick in the book at the house to meet lofty green goals: 65 percent energy independence — meaning 65 percent of all energy needed to run the house will be generated on-site.

Rick Hunter, managing principal for Sage, calls it his “near-zero” showcase house. “Our next showcase house will be a zero-energy house,” Hunter said.

A zero-energy house would have all the energy needed to live in the house generated on-site.

Hunter also wants to build a carbon-neutral house, one that won't emit any carbon dioxide, which is produced from appliances, heating and cooling systems and other daily activities.

Using high-energy appliances, preventing energy leakage and utilizing natural energy such as solar or wind energy can help reduce carbon emissions.

This is the first near-zero house being built in the area, said Jay Swoboda, project manager for St. Louis-based Ecourban Homes and chairman of the green house subcommittee for the local chapter of the U.S. Green Building Council.

“People are feeling the pinch of fuel costs but our utility costs are still among the lowest in the country,” Swoboda said. “When people start feeling the pinch of higher prices, they will realize their house is a big area where they can conserve energy.”

Hunter doesn't have a buyer lined up yet, but that was intentional.

“We didn't want to pre-sell the house because we wanted to build it the way we thought best,” he said.

His goal, Hunter said, is to be at the forefront of green building in the St. Louis region.

“We want to build houses that are as green as possible,” he said.

In this house, that was done first through creating a tightly sealed exterior.

“Every crack, every seam, the floor, any spot where there is any possibility of air coming in, is sealed to minimize energy loss,” said Jim Thomas, senior construction manager.

Then came the usual trimmings you would expect from a green house: water-permeable pavers in the driveway, dual-flush toilets, high-energy light fixtures, sustainably harvested wood products and energy-efficient windows. To achieve his near-zero goal, however, Hunter brought together several other features not commonly used in house construction.

• Sun tunnels: The house has tunnels in the attic. Using a system of mirrors, sunlight is directed through various parts of the house that wouldn't otherwise get it.

“At night, it actually amplifies the moonlight so it will provide some light even if it's not very bright outside,” Hunter said.

The house also has skylights in several rooms, which further reduce the need for electric lights during the day, while the high-energy glass panes prevent heat loss.

• Photovoltaic panels: The house also uses the sun to generate its own electricity, whether for light or to run appliances. Photovoltaic panels — more commonly known as solar panels — cover most of the available space on the south side of the roof.

The sunlight absorbed by the panels is converted to electricity. When the house uses less electricity than it is generating, the extra power is stored in a back-up battery unit in the basement and can be used at night or on overcast days.

Once the battery is fully charged, Hunter said, the extra energy is put back onto the electric grid and the homeowner can get credit for the amount of electricity the house generates. The unit's computer also monitors energy usage and power distribution in the house.

“It can pinpoint any areas that are in need of maintenance by keeping track of how much electricity is being used,” Hunter said.

• Geothermal heating and cooling: Using latent energy in the earth also helps reduce energy use. Water is drawn from five, 200-foot wells in the backyard, Hunter said. The water is circulated by a pump through a series of pipes. Energy is extracted from the water and used to heat or cool the house.

The residual heat is used for bathroom and kitchen fixtures.

“Even when you are using the system to cool the house down, there is enough heat generated during the process to help heat the water,” Hunter said.

A high-efficiency, tankless water heater provides back-up.

The house is expected to have total energy consumption of $140 a month, Hunter said, which he estimates is about a third of a similar-sized typical house.

The extra features add about 10 percent to the cost of building of the house, Hunter said. But as the market grows, he said, it will be possible to build green houses, even ones using solar and geothermal energy, in any price range and without much additional cost.