The nation's burgeoning interest in all things green and sustainable has inspired a team of interior designers at the 2008 Showcase House opening Sunday in River Forest.

The Oak Park River Forest Infant Welfare Society's 36th annual designer showcase puts the spotlight on 18 individual rooms designed with a Mother Nature theme by 16 Chicago area interior designers.

This year's setting is a 30-year-old classic English-style, brick-and-stone house with 12,000 square feet of space. Builder and owner Bob Allen of Allen Builders in Oak Park has spent the last two years rebuilding the 5-bedroom, 6-bath home, including removing the entire roof and raising the second floor ceiling.

The home has all new floors, walls, kitchen and baths and a stunning updated floor plan that includes a second-floor loft and a jaw-dropping lower level that looks like a miniature underground shopping mall.

Allen volunteered the home to the Infant Welfare Society for the designer showcase, which raises funds through ticket sales ($25 in advance; $30 at the door) and is open to the public through Sept. 28.

All of the interior designers donated their time and resources to transform the home into an elegant showpiece. After the open house, the home will be for sale priced at $3.4 million, minus the showcase house furnishings.

Interior design trends come and go, but the nature theme remains on the designers' palettes, said interior designer Gail Prauss, design chairperson of the 2008 Showcase House.

"As design chairperson, the only thing I requested of the designers is that they have a nature theme," said Prauss, president of Gail Prauss Interior Design Ltd. in Oak Park. "There is a strong movement in green design today and the natural materials and fabrics lend themselves to going back to nature to bring the outdoors into interiors. People are working so hard today and the minute they walk into their homes after work, they want to relax and have a tranquil setting and the sense of the outdoors adds to that sense of relaxation."

Prauss said many of the designers used natural fabrics such as silk, linen and wool. The designers also used colors such as greens, blue, golden yellow, beige, taupe, brown and other earth tones as well as metallic paint colors such as bronze and silver.

Many of the rooms have a leaf or flower pattern on everything from the walls, bedding and curtains to couches, winged-back chairs and pillows. Another trend is the use of custom-painted designs on the walls and ceilings.

"The design themes also have a lot of texture as opposed to patterns and a skillful juxtaposition of old and new furnishings and shiny and dull," Prauss said. "One enhances the other."

The Showcase House also hosts a designer sale, where designer items of all price ranges used in the showcase house will be available for purchase.

There also will be a boutique sale in the home's garage featuring arts and crafts, jewelry, sculpture and antiques from more than 30 local artisans, designers and vendors.

The boutique sale is open to the public and does not require showcase house ticket purchase. Proceeds from the showcase house will benefit the society-sponsored Children's Clinic, which provides dental, medical and social services to children from infancy to age 19.

Here are some highlights of the River Forest Infant Welfare Society Showcase House:

Living room: Blending classic and contemporary furnishings within a color scheme of warm browns, brownish yellows and gold helped designers Rod Maxwell and Debbie Weber of R.A. Maxwell in Chicago create a tranquil setting.

The room's walls were painted a cream color and then combed with a chocolate brown for a rich, textured look. Other room highlights include: a leopard-print ottoman, zebra-print French chairs and sheer off-white checked drapes.

A large fireplace screen rests behind a brown sofa at one end of the room and a grand piano dominates the other end. A fireplace screen has leaf accents in keeping with the nature theme.

Dining room: To create a comfortable but elegant ambiance, interior designer William Walker of Barley Twist in Oak Park complemented the round dining table with lushly-stuffed club chairs. The color scheme includes olive and gold tones and blue-and-white porcelain accents throughout the room.

Kitchen, breakfast area and family room: Marilyn Akins Interiors in Oak Brook designed the three spaces. The kitchen and breakfast area have a golden-beige theme highlighted by hand-painted walls with a leaf motif designed by Marilyn Akins and painted by Caryn Akins.

The area also has a handsome antique Persian area rug and a collection of blue-and-white porcelains. The adjacent family room mixes several plaid patterns found on furnishings such as the couch, a pair of wing-back chairs and drapery.

The room is anchored by an armoire and antique red-and-blue rug. Blue and white porcelains in lamps and accessories complete the aesthetics.

Bohemian tea room and library: "I call it Boho Luxe style, as in in bohemian and luxury with gypsy and traditional influences," said designer Leeann Heininger of Fringe in Oak Park.

The comfortable and fun room has a color scheme incorporating raspberry pinks, citrine greens and teal blues. The room's lily-patterned wallpaper is enhanced with a trio of large beige ceramic lily sculptures clustered on one of the walls.

Master suite: This romantic, tranquil and unique room is one of the best in the house. Designer Sal LaPorta of Designs of the Interior in La Grange made the room stand out by placing the master bed in the center of a corner of the room.

To the left is a tall, oversize cherry fireplace with a generous marble surround and flanked by comfortable, contemporary chairs.

LaPorta, with assistants Ania Fraciszkowicz, Diane Racine and Elaine French, bathed the room in a soothing palette of soft golds, blues, greens and browns.

The walls are a soft gold faux finish and the cathedral ceiling features a hand-painted medallion surrounding an elegant crystal and glass chandelier. The room also has an antique walnut armoire, chaise lounge and a hand-painted Bombay dresser.

The adjoining master bath features a Damask wallpaper and soft window treatments behind the large whirlpool tub.

Guest suite: Celeste Mariotti of Mariotti Interior Design Studio in Oak Park says she used a blend of "Gustav style" designs, which were embraced by the Swedish aristocracy and King Gustav III from Italian, French and English courts in 1775-1792. The soft gray-white finish on this furniture complements the rich gray painted walls and ceiling. Other highlights include: white linens and yellow accents on bedding, pillows and drapery and a gray-and-white Swedish rug.

Lady's retreat: "I wanted to create a room where the lady of the house could go to cocoon and relax in privacy," said designer Marge Ericksen of Mixed Company in Oak Park. The second floor room has a large balcony-like opening to the home below.

To create a comfortable getaway, Ericksen painted the walls dark brown and had large bees painted in metallic gold. The gold silk couch is a reproduction of Princess Diana's couch. The room also has a writing desk and a long Hungarian pine table adorned with antique mercury glass bottles.

Other participating designers are: Jessica Henn, Crusiet Corp. (foyer and exercise room); Gail Prauss (first-floor powder room); Jae Berni, Jae Berni Interiors (study/sitting room and hall bathroom); Janet Debits, J.R. Interiors (guest bedroom and hall bathroom); Schuler Wettstein, Within Your Reach (bedroom); Christine Baumbach ("Green Teen" retreat); Marti Napolitano, MNM Design (second-floor family room) and Doug Springer, Rave Wines (wine cellar).