At the time, though, going green was much easier said than done.

"It was frustrating," Ballantyne says. "There was nowhere around here you could go to see the stuff. I spent a lot of time researching online and on the phone, getting these little 2-inch-by-2-inch samples sent.

"It blew my mind that it was such a difficult process. I thought, 'There has to be a better way.' " So Ballantyne opened the Environmental Home Store, launching it out of a garage on his property in 2005.

Last fall, the business moved to a sunny storefront in Mount Airy, where the offerings include building materials made from wheat and sunflower hulls, countertops fashioned from recycled paper, tile made from recycled glass, and several lines of nontoxic paint and wood finishes.

In a sign of how quickly the green-building movement is growing here, Ballantyne now has competition from two other supply houses.

Green Depot, part of a Brooklyn-based chain, took over a former carpet mill in Tacony last summer. And in September, Greenable opened its Market Street showroom in Old City.

Another sign of the times, one likely to help boost business for these eco-entrepreneurs, are the just-released REGREEN guidelines, the first comprehensive resource on green home remodeling.

A collaboration between the American Society of Interior Designers and the U.S. Green Building Council, REGREEN (www.regreenprogram.org) is organized into the 10 most common renovation projects - kitchens, baths, additions and so on - and offers detailed case studies of completed green projects, advice on choosing products, and more.

"It's all very exciting," says architect Lené Copeland, whose firm, L2 Copeland Design, does green projects here and on the West Coast. "Having these stores that people can actually walk into and look at and feel the materials is so important."

Just as crucial, Copeland says: "The people working at these places are knowledgeable. You can talk to someone who can lead you even further into the vast amount of products that are available now."

That's what Monique Mason found when she worked with Copeland on the green renovation of an Old City storefront.

"It really was a collaborative process," says Mason, a hairstylist who opened Moko, an eco-friendly salon and beauty-products boutique, in the space this month.

On a visit to Green Depot, Mason found a showroom employee who was a font of knowledge on insulation, helping her select a cotton batting made from waste created in denim manufacturing.

At Greenable, Mason and Copeland talked over flooring options with co-owner Angelo Anastasio and chose Marmoleum, a linoleum product made from linseed oil.

"I talked to Angelo a lot during the project," Mason says. "He told me, 'You'll have contractors who want to do it the way they've always done it. You'll have people who will say, "Just use this product, it's cheaper and easier, and it won't make a big difference." ' But you really have to stick to your standards."

(Mason ended up firing her first contractor, who scoffed at the idea of using denim insulation.)

Inside the Greenable showroom, the walls are painted a vivid orange hue made by Yolo Colorhouse, one of several companies offering nontoxic, low-odor products free of the nasty chemicals and solvents often found in paint.

"One of our biggest challenges is how do we display it all," says Anastasio, making a sweeping gesture to indicate products lining the walls and arrayed around the store.

Among the offerings are flooring made from cork, bamboo and reclaimed or sustainably grown wood, rubber tiles made from recycled tires, and a spray foam-insulation product made from soybeans.

A countertop line, made from recycled paper and cashew-shell-based resin, includes a pale-green color made from old money and a charcoal color made from newsprint.

There are panels made from wood scraps pieced together like a mosaic, and intricately patterned kirei board, an engineered panel made from the pressed stalks of the sorghum plant.

Though such products are increasingly competitively priced, "green" remains a complex concept when it comes to building and renovation, says Anastasio, who met his business partner, interior designer Lynne Templeton, at a Delaware Valley Green Building Council event.

Many criteria are considered when deeming a product truly green, including what it is made of, how it is made, how it is packaged and transported, and how it can be disposed of at the end of its useful life.

"Also part of the idea . . . is that you want materials to be durable and easy to maintain," Anastasio says.