ORLANDO - If any one word applies to the 2008 New American Home, it's green.

So green "St. Patrick himself should be cutting the ribbon," says Philadelphia-born Bill Nolan, vice chair of the committee that conceived the show house for this year's International Builders Show, which ends tomorrow.

A bit of the blarney? Perhaps. Though houses built over the last 24 years for this event were designed to showcase products and construction innovations, the "greenness" of this year's 6,725-square-foot entry was designed to coincide with yesterday's launch of the National Green Building program, aimed at bringing environmentally conscious practices into the industry's mainstream, and the Certified Green professional designation.

The list of eco-sensitive innovations featured in the New American Home is lengthy. They range from pine needles used as mulch for the gardens of native plants to R-20 Icynene spray-foam insulation, used to turn an unvented attic into conditioned space only six degrees warmer than the house on the hottest day, instead of 150.

Green is also the color of the money needed to purchase this New American Home, which carries an asking price of $4.8 million. But though Florida is mired in a housing bust right now, the builder, Charlie Robertson, isn't worried about it selling.

"Doctors," Robertson says, are the high-end buyers he's targeting. Just five miles away, on the other side of Lake Nona, is what is being called a "medical city," with the University of Central Florida's new medical school, a new Veterans Affairs hospital, and a new children's hospital.

Robertson has been building homes since 1986 with his wife, Judy, a native of Chester. His son Steve was the contractor for the New American Home at the Waters Edge subdivision, where each of the 11 lots sells for $1.5 million.

Steve Robertson's job was a tough one: In just 10 months, he had to complete a massive four-bedroom, 4½-bath dwelling that would normally take two years to build.

Though some call the house "plantation-style," its architecture reflects the vernacular of the Gulf Coast of Mississippi and Louisiana. That was Judy Robertson's idea.

"Hurricane Katrina destroyed so many of those houses that I thought we should do something to preserve the style," she says. "Florida already has enough Mediterranean-style homes."

Dan F. Sater 2d, principal of the Sater Group in Bonita Springs, Fla., designed the house. And though industry experts are beginning to counsel struggling builders to put up smaller homes, this one is all about volume, with 12-foot ceilings and two-story window walls.

"Each room has its own purpose and function, and the scale of the room reflects its function," Sater says. For example, the second-floor "club room" has a home theater; a wet bar with microwave, under-the-counter refrigerators and wine cooler; a fireplace (one of five direct-vent propane fireplaces throughout the house); a game-table area, and access to a balcony and sunporch.

The ground floor's "leisure room" follows the same plan. Glass sliding doors open to a space that features an outdoor kitchen, a covered loggia, and a Solana outdoor sunroom. Sater uses the outdoor spaces on both floors to expand the indoor space, in keeping with weather that permits year-round outside activities. Both areas overlook an Endless Pool that uses salt rather than chlorine.

Interior designer Ron Nowfel, of Robb & Stucky Interiors in Altamonte Springs, Fla., created treatments for an endless variety of window configurations, including a two-story window wall in the grand salon that is draped in silk from floor to ceiling.

Nowfel also chose the colors for the first floor: Sherwin-Williams' Compatible Cream for the walls and Full Moon for the ceilings, both low in volatile organic compounds.

Some ceilings feature accents of cypress, a renewable wood harvested on plantations in Florida that has long been prized for its insect-resistance.

Dark Brazilian cherry - prefinished to reduce the quantity of materials and waste, and less detrimental to indoor air quality - is used in the bedrooms, home office, hallways and foyers. Marble tile, slate and stone are used for floors elsewhere.

In the kitchen, the Timberlake cabinets have a cognac finish. There are two dishwashers, four sinks (each with instant hot water), a warming drawer, two convection ovens, and a six-burner gas cooktop with a device for filling deep pots with water.

Appliances, including two sets of washers and dryers (one set steam-equipped), were furnished by Whirlpool Corp., which included KitchenAid and Jenn-Air Energy Star products.

Solar hot water is available on one side of the house, while Rinnai tankless heaters provide it for the other side.

Impact-resistant glass, steel and concrete "will make this house where we come when there's a hurricane," Judy Robertson says.

She also points to the "his and her" commodes in the first-floor master bath (which has heated tile floors).

"The woman's toilet is actually a Kohler [as are all the plumbing fixtures] with bidet features, and the door has a Rainglass insert to let her look out without anyone being able to look in," Robertson says. "No more worries about the seat being left up."

A water wall and plants in the master bath "give it a garden feel," she adds.

Two second-floor bedrooms are decorated for a daughter and son. Off the kitchen is a suite with its own kitchen and living area that could accommodate an adult child, an elderly parent or a caregiver. The house comes equipped with a two-story elevator.

"I think we have a lot to brag about," Charlie Robertson says of this New American Home, checking to see that a refrigerator door has been replaced so it swings all the way open without hitting the counter.

"It's our most expensive house yet," he says, "but still someone told me last night that I wasn't charging enough."