It looks like any other house in the newly built Gaithersburg neighborhood of $160,000 homes, but the changes you can't see from the outside could make a tremendous difference to the natural gas industry as it tries to convince builders to reconsider the strong trend toward electric heating and away from natural gas.

These changes also could stimulate the market for gas-powered appliances ranging from stoves and clothes dryers to point-of-use water heaters or even countertop cookers, the gas industry hopes.

Taking a cue from the Japanese and the British, the Gas Research Institute, which is based in Chicago but has an office here, contracted with the National Association of Home Builders Research Foundation, also located here, to test two alternative interior piping methods side by side with the kind of pipe commonly found in U.S. homes.

GRI is particularly encouraged by an innovation introduced into widespread use in new construction in Japan about two years ago -- a flexible, lightweight, plastic coated, corrugated stainless steel pipe that would bring natural gas from its point of entry into a house to each room without requiring a single elbow joint or connection.

A soft copper tubing in use in the United Kingdom, similar to a product used by a handful of U.S. utilities, also is being tested in the Gaithersburg home.

The coated, green steel pipe, developed by the Tokyo Gas and Osaka Gas Utilities, delivers gas at two pounds per square inch, much higher than the 0.25 PSI delivered by the threaded black steel pipe common in this country. The test piping is hung from the rafters of the basement by simple metal loops, but one home builder said that one of the house's framing members could be built at no added cost with a lip to hold the pipe, making the hangers unnecessary.

Washington Gas Light Co. spokesman Thomas Julia says his company can easily handle the interior piping because the in-ground gas lines installed after World War II operate at even higher pressure. However, Julia and GRI agree that some older inner-city neighborhoods around the country served by older feeder lines could have trouble maintaining the higher pressure needed.

The interior pipes in the Gaithersburg house end in each room in a receptacle looking much like a covered electrical outlet. In the bedrooms, the outlet could be used to plug in a space heater; in the bathroom, a spot water heater could warm just enough water for a shower; and in the kitchen, an outlet is available for a countertop cooker, such as the ones used in Japan to boil rice.

The test house even had the interior piping installed as a retrofit in the new kitchen as a test of the system's potential for remodeling. And a plug also is available by the backyard deck for a barbecue grill that would operate much like a bottled gas grill.

In showing off the demonstration house, Marlon McClinton, project manager for distribution research at GRI's headquarters, pointed out that there are three built-in safety features to the Japanese system.

You cannot turn the gas outlet switch to "on" unless an appliance hose is securely plugged in; you cannot remove that hose unless the switch is off, and a pressure gauge automatically cuts off the gas if the pressure drops, as might happen when a hose ruptures. The British system also has the first two safeguards.

In addition, striker plates are used to prevent a homeowner from driving a nail through the pipes, and plastic sleeves are used to snake the piping between floors.

"The key word is 'option.' The gas industry wants to give the builder a choice," stresses Tom Leuktenburg, a GRI spokesman.

The gas and electric industries have long been feuding over who has the best system to offer; if the demonstration method of piping natural gas throughout the home is accepted by code officials and catches on with the public, the battle for the attention of consumers and builders is sure to heat up.

Don Luebs, director of building systems at NAHB's research foundation, which also counts the electric industry among its many clients for other studies, says that a successful test of the flexible pipe should give "lots of encouragement" to the gas industry. "The old black iron is a primeval product; it's a bear to get around inside a new building."

GRI also is working on developing a new line of meters and regulators for multifamily units, the biggest potential problem with the new system that Julia could foresee.

The difficulty the gas companies are having with construction companies is reflected in the fact that more builders of high-rise apartments and inner-city and harbor renovation projects have been relying on electric heating and cooking equipment, particularly as the use of individual metering for homes has risen to 94 percent of the new market.

Connecting all that black steel pipe to allow individual metering is just too expensive, the gas industry readily admits.

However, a study conducted by NAHB/RF on the Gaithersburg test house shows that gas pipe installation costs could be brought down by as much as 30 percent for multifamily high-rise buildings, 22 percent for town houses and 6 percent for single-family detached housing with the Japanese system.

Savings on the time for installation also would come down, by 50 percent, 30 percent, and 14 percent, respectively.

Meanwhile, according to Harry Paynter, president of the Gas Appliance Manufacturers Association (GAMA) trade group, more than three out of five kitchen ranges installed today are electric, while the overall split is still about 50-50. "The gas people want to make it more easy to put gas appliances around the house," adds NAHB's Luebs. "Certainly the new piping method will help."

Just how much could depend on the willingness of code officials around the country to accept the system. Much of the interior natural gas piping code work is based on the technology of the black steel.

In addition, whereas in Japan utilities have a great deal to say about gas and electric codes, the United States has thousands of jurisdictions relying on some six separate code-writing bodies, with each locality having its own code-amending procedure.

In the Washington area, all of Virginia and the outer suburbs of Maryland rely on the standards drafted by the Building Officials and Code Administrators International (BOCA).

The District writes all its own codes, and Montgomery and Prince George's counties operate through the Washington Suburban Sanitary Commission, which also acts independently of the code organizations.

The Gaithersburg test home is too new for many involved parties to have heard about it, much less have seen it demonstrated. A second test home will be built in Orange County, Calif.

Officials from gas appliance trade group GAMA were not familiar with details of the house, and one officer from a major gas-powered appliance manufacturer had never even heard of the idea. However, GAMA's vice president of technical services, Jack Langmead, said he has seen the Japanese appliances and is happy about the U.S. tests.

WGL is even more enthusiastic. Julia says the utility is "encouraged by what we see. We don't know when the appliances will be marketable here, but we'd like to be the first, like to be a leader."