On March 3, 2008, in a quiet rural patch of Snohomish County near Echo Lake, southwest of Monroe, arsonists claiming to be members of the Earth Liberation Front (ELF) burned down three newly constructed, unoccupied, "green" houses, damaging two others. The fires caused over $7 million in damage. No arrests have ever been made.

Which leads to an obvious question: how can supposedly green, eco-friendly houses even be worth nearly $2 million each? Isn't being green supposed to be about, you know, conservation? Living lightly on the earth, and all that? Can that be squared with the destroyed homes, which ranged from 4,250 to 4,750 square feet?

The ELF arsonists certainly seemed not to think so. The banner they left behind claiming responsibility declaimed "Built green? Nope. Black. McMansions in RCDs r not green"--referring to a controversial program called Rural Cluster Developments, in which enormous new developments built in rural areas qualify for "green" certification in part by spacing the houses closely together and leaving an offsetting, undeveloped greenbelt intact.

Regardless of what one thinks of the arsonists' tactics, they made visible an ongoing debate in the environmental and green housing communities. How much is too much? What is the balance between wanting to encourage green features in every size of housing development, and acknowledging that our culture's fixation on size, and material consumption, are an inherent part of our environmental problems?

In the case of RCDs, such houses may have the latest in new eco-gadgets, as well as preserving surrounding rural landscapes. But you're still talking about a sprawl-promoting development miles from jobs, schools, and shopping. And you're still talking about new single-family houses large enough for entire Third World villages to live in.

"The real challenge is to transform our culture," says Patti Southard, a project manager with King County's GreenTools green building program. "Why do we want bigger houses and cars in this culture? In Europe more efficient is considered smarter. It's actually a smaller footprint."

That transformation is already underway. In the last decade, green building has become a big business. Built Green, a nonprofit project of the Master Builders Association of King and Snohomish Counties, began certifying green homes in the area in 1999; since then, it has certified some 10,000 homes with up to five stars of greenness. Built Green Executive Director Aaron Adelstein estimates that about 22 percent of new home building in King and Snohomish Counties is now green certified. He wants that number to be 50 or even 60 percent in another five years.

The Built Green program rates new and remodeled homes in four different areas: healthy building materials (important for indoor air quality); energy efficiency and greenhouse gas emissions (or lack thereof) in the structure; green and energy-efficient materials (for example, energy-efficient lumber); and water conservation. With the exception of the amount of materials used, none of these requirements factor in size; nor do they account for siting. That, says Adelstein, is not in Built Green's scope. It's local governments that decide where new housing can go.

"We're not a permitting agency, and we're not a political nonprofit," he says. "There's still demand for living far away from urban cores, and for larger than average housing. That demand is going down, but those types of buildings are still being permitted. We still advocate for those buildings to be built in as green a way as possible."

Southard points out that larger houses need to do more in order for Built Green to certify the development. She echoes Adelstein's sentiments. "Any house should be a green house, especially if you're building a large house. If you're building a custom house there's no excuse any more not to build green. The materials are all there now. We want to encourage every house to be a green house."

Environmentalists agree--but say that still misses the bigger picture. "It's like using paper or plastic. The real question is, you should bring your own cloth bag," comments Kathleen Ridihalgh, Senior Regional Representative in the Sierra Club's Seattle office. "Should we be building on undeveloped rural land? It's great to be trying to reduce the footprint with green building, but you have to look at the whole picture: community design, walking to shopping and schools, and so on."

Jon Alexander, owner of Sunshine Construction, is one of the leading green architects in the area and works with Built Green. He's more skeptical about the Echo Lake project that was targeted by the ELF, noting that it built on wetlands adjacent to Bear Creek, an environmentally sensitive area. "It sounds like it wasn't a very good place to build houses of any size," Alexander notes. "I don't see that as a size issue. They're building really big houses in a bad location and calling them green. A really significantly green building in a bad location is still not a great idea." But Alexander suspects a number of new developments in the area are similarly flawed, and that pressures of population growth make that inevitable. "A lot of the easy land that doesn't have problems has already been built upon," he says.

The Sierra Club's Ridihalgh points to the High Point redevelopment in West Seattle as a project that is in-city, well-located, and built green. But that development, in turn, displaced some of the last remaining lower income public housing in Seattle, raising another question: is building green something only the affluent can afford?

Alexander, an architect, says that's no longer the case. "The idea of green building as being really expensive isn't true. Using passive solar, for example, costs almost nothing. There's things that only cost a little." And many of the investments, such as in energy-efficient materials, pay for themselves quickly.

One of the developments most widely praised in green building and real estate circles is Issaquah Highlands, a planned urban village of 3,250 homes in which all buildings are required to rate at least four stars in the Built Green certification process. Nearly 70 percent of Issaquah Highlands' 2200 acres is open space, with homes and businesses clustered within easy distance of walking and transit. Brad Lillequist, project manager for the City of Issaquah, also takes issue with the notion that green necessarily costs more.

"As industry becomes more knowledgeable, a lot of the construction costs are becoming cost-neutral," he says. "Knowing what materials to specify makes a difference. Those materials may not be more expensive. Wall to wall carpeting, from a health standpoint, is not a good thing. It holds in moisture, it holds in dirt. Maybe we use a lightweight concrete flooring and sand and polish it. That may cost the same but you get rid of the health issue."

The figures bear this out. MLS listings now have a box to check for green certification. Such listings, over the six months ending in March 2008, show local green housing only costing 4.8 percent more to build, and selling for about 10 percent more than non-certified homes in 24 percent less time. The green houses, on average, were also 25 percent smaller than non-certified ones. The economic downturn, of course, has made it harder to sell the more expensive "green" homes--but it's also made conservation that much more attractive.

Built Green's Adelstein claims that the sale price is more a function of demand than actual cost. "I don't know that in this market builders would be able to pass on increased costs for green building unless there was higher demand," he points out.

Who's buying green? "The primary demo is a second-time homebuyer, age 30-40, relatively affluent and well-educated, often young families," Adelstein claims. "They bought a home once, and they're doing it right this time." Ben Kaufman, of GreenWorks Realty, paints a similar picture. "A lot of buyers are professionals -- health care, architecture, in a position to understand the value." And, Kaufman points out, the cost is more a function of the buyer: "People shop by what they can afford."

Issaquah Highland's Lillequist agrees that all things being equal, smaller developments are better. "An eight thousand square foot house consumes a lot more energy. We should try to build it so it's the right size house. You're not building more than you need to build. But at a given size, a 5,000 square foot house with green features is better than one without.

"There is a shifting paradigm about whether we need the second bonus room or the third garage. Potentially the money could be put into a higher quality house that is also greener. I think there's a cultural awareness about livability coming online."

In the end, says King County's Patti Southard, smaller and greener is the direction the market will go -- with or without the taunts of arsonists. As people become more conscious not only of environmental footprints, but of cost savings, health, and quality, the cultural shift she wants is almost inevitable. "In the next ten to twenty years buyers will want the smaller houses, but what we don't need to do is shame people," Southard says. "We need to encourage them to green it up."