The roof and grounds surrounding the building known as GreenForge in Hempfield were white with snow last week. But Westmoreland County's ultimate model of conservation was as green as ever.

That's "green" as in using energy-conserving technologies, best management programs and architectural features so exemplary that 14,000 people a year stop by to see what the building is all about.

Now they don't have to wait for a guided tour or take the self-guided tour around 21 stations that explain GreenForge. A nine-minute video is available to view in the lobby, and soon it will be on the Westmoreland Conservation District's website. In the near future, additional copies will become part of the district's many educational programs.

"We wanted to make the video so that we can interpret these things when people come into the building and we aren't necessarily standing in the atrium," said Greg Phillips, conservation district manager and CEO. "The video explains how we work."

GreenForge is at the Donohoe Center on county property on Donohoe Road, adjacent to the conservation district's headquarters in a reclaimed barn. Also on campus is the building that houses the Penn State Extension Office and several other local, state and federal agencies.

The former warehouse and office space had outdated energy and construction features and was transformed in 2005 into an energy-efficient building that is a model of sustainability. It has been an inspiration to homeowners, businesses, contractors and others who want to build or retrofit existing structures with similar details.

The $2.1 million project was undertaken by a partnership of the conservation district, the Westmoreland Industrial Development Corp. Inc. and the Katherine Mabis McKenna Foundation. It is managed by the nonprofit GreenForge Inc.

The building has 23,000 square feet and a flat roof with 9,000 square feet.

Jim Pillsbury, the district's hydraulic engineer and specialist in storm water management, worked on the project that turned the roof into Westmoreland County's first -- and, so far, only -- green roof. Instead of shingles, the surface is covered with thousands of sedum plants in nine varieties.

"They are a succulent, which means that the plants take advantage of whatever moisture is available," he said. "It would be like a cactus in the desert where you don't get a lot of rain, but the cactus is very efficient in nabbing moisture from the environment."

The sedum plants grow to about 4 inches tall and in the spring, they bloom with a variety of colorful flowers that attract honeybees. They are planted in 2 inches of lightweight growth material laid over a reinforced roofing structure.

"There's no dirt on the roof, so it won't wash off and plug up the drains," Mr. Pillsbury said. "The sedum doesn't have roots that go down deep, and if we have a prolonged dry spell, these succulents are able to survive. They can survive, too, on a day [with] 8 inches of snow on the roof. Right now, they are dormant and brown and shriveled to a certain state, but they don't die."

Green roofs offer many advantages. They are better at regulating building temperatures, keeping heat in during the winter and letting heat out in the summer. They also cut down on repeated freezing and thawing that can damage a roof, and they catch and hold rain and melted snow to reduce water runoff.

The parking lots are drainage friendly, too. The spaces surrounding the building are paved with a permeable mix of rocks, cement and water. Without the addition of sand, the mix forms a rough and porous surface that allows rain and melting snow to seep into the ground.

"We have about 40 inches of rain a year in the county, and the permeable concrete allows 80 to 90 percent of it to soak into the ground instead of 100 percent running off," Mr. Pillsbury said.

Landscaping with native plants and not having curbs eliminates the need for retention ponds, too. The design also works for the adjacent buildings on campus.

A lot of the drainage from the roofs gets absorbed, so underground sewers aren't needed, Mr. Phillips said.

"There were beliefs that you can't infiltrate in Western Pennsylvania because the ground has too much clay, but I can see that it works. So water is treated as a resource and not just thrown into a creek to do some flooding."

The inside building temperature is regulated by a geothermal heating and cooling system with a heat pump. Water circulating through it has a constant underground temperature of about 55 degrees.

A 3,600-watt solar array produces about 7,000 watts of power a day. That's equal to the daily electrical needs of an average family in an energy-efficient home, using natural gas for cooking and heating.

The building itself is well-insulated with densely packed cellulose fiber made from recycled newspapers. Inch for inch, it provides better insulation than fiberglass.

The first tenants moved into the building in 2006. They are the U.S. Department of Agriculture Rural Development, Westmoreland Cleanways, SmartGrowth Partnership, Western Pennsylvania Coalition for Abandoned Mine Reclamation, PSD Consultants for energy conservation, and the Outside-In social work agency for youth.

"A lot of people have come here and looked at GreenForge and learned from us," Mr. Phillips said. "Homeowners have come, and the county is now putting a geothermal system in the juvenile detention center. We get a lot of walk-ins who say, 'I can see it, I can feel it and I can touch it, tell us how it works.' "

GreenForge had influence at the Winnie Palmer Nature Reserve at Saint Vincent College in Unity and in the new Fred Rogers Center there. But, Mr. Phillips said, technology has changed so much in recent years that GreenForge itself can be updated.

The new video will enable the district to expand its energy-conservation program, including campus tours and workshops. For information, contact 724-837-5271 or www.wcdpa.com.

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