Green building in ecovillages: Diana Leafe Christian shares the ups and downs of building simply.

Sustainable building is an inexact science and its adherents are learning all the time. Like other ecovillage founders, we've learned a great deal about what works and what doesn't work at Earthaven, a permaculture-based intentional community on 325 acres near Black Mountain, NC. Like most aspiring ecovillages, we use passive solar heating, roof water catchment, off-grid power, composting toilets, and small homes of mostly natural or recycled materials.

Learning to use natural building materials from your own land is one way ecovillages try to live sustainably. In our own attempt to learn this, we combined several methods in one of our first buildings, a timber-framed Council Hall. We used peeled by not milled logs from the land with either traditional timber-framed joinery or bolted joints, and 26 logs radiating from a central cupola to span a 35-foot interior. Because we wanted to learn several different traditional methods for wall infill, we made the northern walls strawbale, for insulation, and southern walls straw-clay and cob, for thermal mass, with large windows for solar gain. We plastered the interior and exterior surfaces with earth and lime plaster.

Like many ecovillage residents, we began a more ambitious building project than we could finish easily. As a first step towards having a "living roof," we covered the roof with EPDM, a rubber-like sheeting often used for pond liners. And for a while, we had no floor in the center of the building just old carpets over the dirt. Whenever it rained and the wind whipped the EPDM back our roof would leak, and wet carpeting and dirt would create mildew. So anytime after it rained when we'd walk in into our beautiful, natural-built "sustainable" building, we'd get knocked over by the smell, and some people in our Council meetings wore air-filter masks. But nowadays our EPDM is more secure, our floor of red maple and walnut (milled from trees on the land) is nearly finished, and the place smells fine. Let it rain!

Builders at Sirius Community in Massachusetts, another ecovillage project, also tried new methods when they built their 12,000 sq. foot octagonal Community Center. Like us, they timber-framed their building, used a mostly circular shape, and attempted to span a large interior space (in their case, fifty feet.) They also explored innovations, such as a unique wall construction method to reduce the use of wood and reduce heat loss, blown-in cellulose insulation, and two composting toilets. Like us, most of their innovations worked, but they also learned some lessons--their building is warm and toasty in winter and cool in summer, but one of their composting toilets never worked.

Ecovillagers usually build their homes on the same general principles, but suited to the natural materials of their bioregion. In our case, all homes are passive solar heated backed by wood heat or propane (most are on south-facing sites), and many are earth-bermed on the north as well. Most are round-pole post and beam construction with thick walls of straw-clay in fill or lath and plaster with blown-in cellulose insulation. All have green metal roofs, and most are earth-plastered or earth-and-lime plastered in shades of reddish-orange and apricot pink. Members of Dancing Rabbit Ecovillage in Missouri, however, use methods suited to the prairie. Since wood is scarce and straw plentiful, they build their passive solar homes of load-bearing strawbale, and any lumber must be recycled or grown locally. To keep homes cool in summer, they use white metal roofs to deflect the sun's heat, and their earth-and-lime plastered exteriors are a pale cream.

Like many other natural builders, we learned it's not necessary to use chicken wire over strawbales before plastering. In fact, the first coast of earth plaster adheres better if you just mash it directly into the prickly straw surface. We also learned from those that went before us that using such plasters means thinking about the effects of weather, so plastered buildings must have sturdy foundations and wide roof overhangs.

Ecovillage residents are also partial to recycled building materials. One of our homes, still under construction, is an "Earthship," a specialized kind of passive solar building made of recycled tires filled with rammed earth and stacked like bricks into the south side of a slope. Another building under construction, a large multi-family home, uses recycled 4x4-foot pallets sheathed in 3/4" plywood as a major building material. The pallets comprise the sides of four-foot-square plywood and plastic-lined "juice cubes" that fruit juice processors use for shipping. The family hauls the discarded pallets home from a bottling plant in a nearby town, and, using floor joists on four-foot centers, they then drop the pallets into place like gigantic floor tiles for a rock-solid subfloor. They detach the plywood squares from other pallets to use for sheathing the walls and roof. The only down side is that the pallet supply may not last.

Many ecovillage builders use earth as a building material, which also offers lessons to be learned. For example, we learned how to mix earthen plasters (and lime and earthen plasters) with the right proportions of clay, sand, fiber, wheat paste as a binder, a little vegetable oil for smoothness, and a touch of iron oxide or yellow ochre for color; lime washes for interiors; and earthen paints, with flecks of mica for natural sparkle. But we found out that while these look wonderful as interior surfaces, the super-fine dust that seems to settle on everything makes a place harder to keep clean, and some folks are allergic to it. So we ended up covering our kitchen's lime-washed interior with an acrylic sealant, and at least one family has done the same in their cottage.

We also used earth in the soil cement floor of the kitchen and one cottage. But the kitchen, which receives a lot of foot traffic, started to crumble in places, so we replaced it with concrete. It's possible that we have too much silt in our subsoil for this flooring technique, which works fine in other locations. The floor in the cottage, on the other hand, where only one family walks in stocking feet, is just fine.

Much of building sustainably is experimental, and so offers a chance to invent new methods with local materials. Some of our logger-builders created a wall system using the mill ends of logs most lumber companies discard, and found ways to make building materials out of thin trees that most loggers overlook. They're investigating the use of clay slip and wood chips for wall infill, which apparently offers similar insulative value and thermal mass as straw-clay walls, but would be easier, quicker, and cheaper to use (not to mention that a forest bioregion like ours has more wood chips than straw). One member created an alternative cement for the concrete floor of our sauna, using fly ash (from coal burning plants, not waste dumps!), citric acid, lye, and borax. That floor is as hard as a rock.

Another ecovillage goal is to explore what "sustainable" means in the larger sense of the term. At Dancing Rabbit, for example, residents don't just seek to live in natural buildings, but also to reduce dependence on fossil fuels, so they build strawbale cabins and distill their own biodiesel fuel from used fryer oil. And although we want to live in natural buildings, we also want to grow as much of our own food as possible on our 40 to 80 acres of bottom land, now covered with trees. Like ecovillagers everywhere, we don't want to live in one place and use rivers of fossil fuel to work someplace else. So we don't just ask ourselves how can we live in sustainable natural buildings. We ask how can we clear forty to eighty acres for agriculture, use as much of our trees as possible for building materials, generate a village economy and make a living at home--and live in sustainable natural buildings.

What Is an Ecovillage?

One of the most widely used definitions of ecovillage (by Robert Gilman of the Context Institute) is a human-scale, full-featured settlement in which human activities are harmlessly integrated into the natural world in a way that is supportive of healthy human development, and can be successfully continued into the indefinite future.

Scholars like Gilman say there are no existent ecovillages, since none meet all the criteria yet. Some of the more well known ecovillage projects in this country are Ecovillage at Ithaca in New York state, Dancing Rabbit in northeastern Missouri, Sirius Community in western Massachusetts, Lost Valley Educational Center in Oregon, Los Angeles Ecovillage, and Earthaven Ecovillage near Black Mountain, North Carolina.

Hands-on workshops at Earthaven: Introduction to Natural Building: Materials, Methods, Systems, (May 23-25) cob, strawbale, earthen plasters, and timber framing; Creating Sacred Space with Feng Shui, (June 21-23); Building with Cob: An Introduction, (July 19-24). 828-669-393; [e-mail]; www.earthaven.org (see New Life Events in this issue for more events). Diana Leafe Christian is a member of Earthaven Ecovillage and editor of Communities magazine.