"We're standing on what used to be a parking lot," Jon Allen says with a satisfied smile.

That means the scene you see today -- plants everywhere, amid deep squishy layers of mulch that feel like a trampoline to walk on -- used to be a place where a summer rain would wash the oil and other chemical drippings from the bottoms of cars into a nearby marsh and pond. And this in a city park.

Today, the surface of that parking lot has been bashed and crumbled into an invisible base that lies buried beneath a new environmental learning center that is due to be finished by the end of November.

The learning to take place at this center, city officials emphasize, is not just that of kids squirming on the floors as they wait to put on snowshoes and search for deer and coyote tracks in the woods outside. The goal is for adults, including homeowners, public officials, and builders and developers, to see a building and grounds that treat nature with real respect.

"We want to use this as a model so when builders come in, we can bring them there," the city's administrator, Barry Stock, told a gathering of Scott County civic leaders a few weeks ago. "They're afraid of some of these things. What's a 'rain garden?' Most people think it's a weedy patch of grass, but if properly maintained, it doesn't have to be that way.

"And we want to make the point that it can actually save money. If you put in pervious pavers," a Rice-Krispie-bar-like layer of compressed gravel that lets water seep straight through to the ground, "you won't need to use an entire acre of that expensive property on County Road 42 for a storm pond. You can do the same thing in other ways."

Area homebuilders and environmentally aware businesses say they are seeing a greening on their side already. The Builders Association of the Twin Cities, for example, announced the winners of a first-ever "Green Building and Remodeling Award" this fall. The group's spokeswoman said it is working on a green certification program.

And Haley Comfort Systems, a Forest Lake company selling geothermal heating systems such as the one the new center in Savage uses -- a more costly system that pulls heat from the earth but pays for itself within several years and doesn't use fossil fuels thereafter -- reports "big time" interest in that technology already among homeowners.

Savage's center, built with the help of a major grant from the Jeffers Foundation, is designed to be inviting enough to attract wedding receptions, even though the look will seem strange to some. The walls are made of wheatboard, or squeezed-together chaff from fields of wheat. The ceilings are a substance that resembles a Ramen noodle chunk and consist of fibers left over from aspen trees when the wood-products industry is done with them.

Outside, meanwhile, instead of having sprinklers using up treated water while rainwater whooshes pollution into the pond, sidewalks and parking surfaces are tilted so as to divert that water into a sunken, foot-deep layer of mulch. Plants such as coral bells sustain themselves on it, and the rest slowly filters, cleansed, into groundwater. The goal is for water to disappear within 24 hours, leaving -- unlike storm-water ponds -- no time for mosquitoes to breed.

The building also has a "green roof," planted with sedum and other vegetation, which will soak up much of the rain that strikes it. Kids will be able to use computers to monitor that process: how much water falls, how much is sucked in and so on.

The woods outside, meanwhile, are slowly changing: Trees with Dutch elm disease are being felled, buckthorn ripped out, and maple trees planted that eventually will yield syrup.

It's a place that works, Allen said, on all sorts of levels, and it will house everyone from classes in schools to retired people sipping on coffee in soft chairs as wildlife are drawn to feeders outside.

"The whole site," he said, "is a teaching tool -- a way to spread the word."

After how many years of planning?

"Funny you should ask," Allen said. "I just went back to my files and looked it up the other day. Planning began in 1991," a year when today's high school seniors were still learning to walk.

David Peterson • 952-882-9023