The National Association of Home Builders Research Center has initiated a research project to see just how far America is from producing an ultra energy efficient - "Net-Zero" - fossil fuel home.

According to project leader Joe Wiehagen, home builders, appliance manufacturers and energy technology leaders have made substantial individual strides over the past decade to make their products more efficient.

Wiehagen's research will attempt to combine all those technologies, see how much they cost vs. how much they save, and come up with an idea on which way the industry should be heading.

"We wanted to see where we were on the scale toward building something like this," said Wiehagen. "We want to see where we are with energy consumption and energy production to see if net-zero is possible."

At its simplest, the Research Center wants to determine if a home could be built that is so energy efficient that whatever power it uses off the public utility grid can be 100 percent replaced by the power the home produces by use of things like photovoltaic cells.

Says Wiehagen, "We want to see if we can get the electric meter to run backwards."

In some areas, and by law in some states, energy-producing homes may be hooked up to the power grid. In that way, the utility is used as a sort of "energy bank," where a home might "withdraw" power from the grid during the day to run appliances, heating systems etc., but then send power back into the grid during the night.

He added that the give-and-take time period would not have to be just 24 hours. "In the north, your home might need a lot of heating during the winter, but it wouldn't need a lot of cooling during the summer." Like putting energy in a bank.

Wiehagen said his project would ultimately would be turned over to economist to factor in a variety of cost components to get an accurate picture of costs. For instance, photovoltaic cells, at their current cost, may not pay for themselves for 30 years. Windows that are energy efficient may save on power use, but they also may cost 30 percent more than regular windows.

To some extent, however, Wiehagen is comfortable that over the years America has become "greener."

"Federal regulations demand that new refrigerators be more efficient, and washers and dryers," he said. "And builders know that different parts of the country need different levels of insulation. There is a growing sensitivity out there."

By the same token, however, the same old problems continue to drag down movement toward widespread production of energy efficient homes: The technology is expensive and not quickly recovered, some builders don't know how to adjust designs to maximize efficiency, and not all tradesmen know how to properly install energy-efficient systems.