Imagine a wood-burning stove that completely utilizes all particles of wood fuel, so efficient that the final product exiting the chimney is a woody smelling steam. The experimental, hand-built Rocket Mass Heater is just that stove. By essentially putting a highly insulated chimney inside the stove itself, and then directing the heat through pipes running throughout the house, Rocket Mass Heaters can greatly improve the environment by using less than a third of the wood than traditional wood stoves, in addition to reducing smoke pollution and carbon emissions.

Although this design is somewhat new and can be considered experimental, a few brave north coast residents are convinced that this form of heating is the way to go. Rocket Mass Heaters use significantly less fuel to heat, and make the most of the fuel that is used. That, coupled with the fact that they can be hand-built by individuals with no previous skills, using household items and resources readily available, for a cost of less than fifty dollars, make Rocket Mass Heaters a viable step toward improving the environment whilst safely and comfortably heating north coast homes.

It’s difficult to talk about Rocket Mass Heaters without discussing natural building, and cob building in particular. Cob building is a very simple, ancient technique that uses local soil, mixed with sand and straw (used in its longest possible state) to create a tough, insulated and hand-formed finish. Although cob is not essential to the design, part of what makes Rocket Mass Heaters so enjoyable is that they can effectively heat and keep warm hand-built furniture and walls.

Mendocino resident Stephanie Silva has an incredible naturally built clay and wood-chip based studio nearing completion behind her house on Little Lake Road. Featuring the exquisite craftsmanship of local contractor Isvi Aum, the studio was built with sustainability at the forefront. Every little bit of the locally harvested wood was utilized in the process, from the magnificent cross beams to the tiny slats which hold the clay and wood-chip insulation. After making a series of smaller cuts for lumber, Aum then chipped up the rest of the locally harvested trees to be mixed in the clay. A Rocket Mass Heater, with a large warming bench, is a centerpiece of her studio. Silva entered into the project through her own curiosity, and the project, which has been ongoing for the past year, has provided her with the opportunity to work with neighbors and new friends in a unique way of community building.

“The idea of the rocket stove came from the book, ‘The Hand Sculpted House’ and from helping to build a house with one in it. Then I read the book ‘Rocket Stoves’ by Ianto Evans, and Leslie Jackson. I e-mailed Leslie and she put me in touch with Kirk Mobert from Point Arena who has turned out to be another amazing teacher. He is a truly intuitive natural builder and pyromaniac. I say that with the utmost respect. You have to be a pyromaniac to have a rocket stove function properly. The best thing Kirk did was to abandon me at the end of the stove-building project. I think he knew that I needed to actually put the thing together in order to understand it. Now I am intimately involved with my stove and feel totally empowered by that relationship.”

“A Rocket Stove is a thermal mass heater which burns a small hot wood fire then forces the hot gasses through exhaust ductwork built into some kind of thermal mass heat storage. Ideally this heat source is either a bench, couch, floor or wall where you will actually be in contact with the heat source, mine is a bench/ couch/ nap zone… I had to have a warm bench I could nap on. It takes several hours to heat up but once it’s warm it stays that way for up to twelve hours.”

“In Guatemala in the seventies, I developed the Lorena stove system, which uses a sand-clay amalgam to contain the fire, hold up the pots and store surplus heat. It rapidly attracted worldwide attention and is now widely used in Latin America, Asia, and Africa. Later, I worked as part of a team in over twenty countries, helping people create better cooking facilities. I spent much of a decade in villages, in people’s homes, mostly with the women who actually do the cooking. One result of my experience as a professional pyromaniac was some work in the U.S. on the challenge of improving wood-fired heating stoves for cold climates.” Ianto explains that traditional wood stoves are basically fireboxes with an exhaust pipe attached. “To be optimally heated, you would need to be staked out on the ceiling directly over the stove. In general, the more heat lost out of the top of the chimney, the better the combustion…Our goal in developing Rocket type stoves was to rethink completely the question of how to burn wood inside a house in order to improve human comfort, use less firewood, and cut out pollution.”

I first learned of Rocket Mass Stoves from Kirk “Donkey” Mobert, a born and raised Mendocino Coast resident who, in the past five years, transformed himself from computer tech geek to a Natural Home Building expert. “I had to quit computers,” says Mobert. “I started hating it. I was fifty pounds overweight, my wrists were shot, my eyes were shot, my back was shot. Sitting in front of a computer, working long, long, long ugly hours will do that to you. I had a bit of a mini-crisis, and went into construction.” He attended a two-month hands-on intensive with Ianto’s Cob Cottage Company in Coquille, Oregon, and came back a changed man. “I decided that if I was going to do it (get into natural building,) it was time to get started.”

Mobert, who is a bit of a self-taught genius, built his own Rocket Mass Heater without the benefit of Ianto’s book, which he helped write. He built his beautiful and effective stove based upon seeing a Rocket Stove at the workshop in Oregon. “I invented it as I went along, building from the bottom up. At one point I got hung, the idea is a simple one but it can be hard to visualize fully. So I called Ianto in a panic one night and he gave me the ten-minute synopsis. ‘The chimney’s in the stove, dude.’ That was it, everything pretty well clicked after that.”

Mobert’s enthusiasm for natural-built homes is infectious. “The whole point of natural building is based upon using resources that are available onsite,” says Mobert, “that, and the fact that you can do it yourself. It’s a great way to conserve, and, it allows us a way to create a non-toxic environment for our families.” In his book “The Hand Sculpted House,” Ianto mirrors this concept. “The fact is, if you build with toxins, you have toxic waste. If all your materials are natural, anything coming onto the building site can stay there, no, we don’t have the big essential of every construction site—we don’t need a dumpster.”

Not all of natural building techniques require creating a new building. Mobert actually got his professional start finishing off the bathroom in Pangaea, a highly regarded restaurant in Gualala. He used a natural cob mix made from local clay, composted horse manure, and natural pigments to create an earth-based plaster in the bathroom. The result is a long lasting, beautiful and very rich looking surface.

People interested in a more natural environment may want to look into painting with natural pigments and plasters. “My four-year-old mixed these paints,” says Mobert, pointing out a door showing test strips of color. This stuff is completely non-toxic, and it can last a long time, depending upon the mix. There are lime frescos in Europe that have been in place for years.”

The colors that Mobert reveals are all incredible, and it is easy to see how one could create variations to please their own color palate. Best of all, this type of paint does not require a special trip to toxic waste removal sites to dispose of the extras. Eliminating inconvenience, yes, but, the fact that we commonly use substances in creating our homes that are too toxic to be disposed in a regular dump speaks volumes.

Michael G. Smith, as previously mentioned, is one of the authors of “The Hand-Sculpted House” who lives in an intentional community in Boonville called Emerald Earth Sanctuary. Emerald Earth Sanctuary is a center for natural building techniques, and offers workshops and work parties, which offer people an opportunity to learn natural building techniques for free. “I’m really interested in the impact of human beings living on the planet,” says Smith, and therefore “I’m interested in finding and promoting ways that people can use fewer resources and thus have less impact. Natural building can be a good means for that. The materials are less processed and require less energy to manufacture and transport.

“Living in community is a good way to reduce natural resources as well. For example, we have six households that share one washing machine, one chain saw, one refrigerator, and one truck. And I could go on from there,” Smith says with an obvious joy in his voice.

The issue of permitting comes up often around natural building. “There are many people using natural building techniques in the county,” says Smith. “Not all of them choose to get building permits. There are many reasons for this, perhaps one of the biggest is to save money…it’s usually cheaper to build without a permit, especially due to the requirements to have a septic system in place. Not everyone wants to have a septic system, and they can be very expensive. Zoning is another issue for some, in parts of the county, the minimum lot size is enormous, 160 acres for land designated as forest and range, for example. Finally, not getting a permit allows people to do more experimental kinds of building.”

hniques. “In fact, the first permitted cob-built house in the country was built in Mendocino County.” Smith references Class K permits, unique to Mendocino County, as making the process of permitting natural buildings in Mendocino County. “The whole permitting issue is a bit of a red herring,” says Smith, “the building department here is really quite receptive to the idea of natural building, more so than any other place I’ve lived in the country.”

Mobert has strong words to say about permitting. “Building codes were invented for tenement buildings in New York. They were unsafe, and roofs were falling down on people’s heads. Somebody figured out that money could be made through permitting, and now we have this situation where you can go into debt for thirty years to build a house that’s toxic, but you can’t build out of your own pocket, with your own hands, a safe, non-toxic house for your family. It’s a travesty of justice,” says Mobert.”

Natural Building and Rocket Mass Heaters are not for everyone. Although they do save on the environment, the costs associated with naturally built homes are generally equal to or greater than conventional techniques. Silva learned quite a bit through the process. “Natural building takes two or three times longer than you think, so I learned patience. The sand we used in the mix is angular manufactured sand so I learned that you should wear gloves when you build a large cob wall if you want to have any fingerprints left at the end. I learned to trust myself, to slow down, to enjoy the process…What would I do differently? Think more about window placement. Use smaller dimension wood for the greenhouse, start with more money!

“Be aware that it could cost as much or more than traditional construction because of the labor involved,” says Silva. “Be honest with yourself about how much time you can take out of your life to build. Take a workshop with someone who really knows what they are doing. Spend as much time as possible on the building site before starting the design process, watch the light through the days, weeks, months and seasons to see where it will hit your building. Be realistic about what you really need to be comfortable, think small.”

Aside from the environmental benefits of natural building, the very process of construction helps to create community. “There’s a very well-connected community of people into natural building,” says Smith. “There are a lot of us who have been doing it for awhile. People can network to get ideas and information for their projects. And, it’s more possible with natural building to find alternative labor sources. There are lots of people wanting to work for free in exchange for learning.”

Silva has hosted numerous natural building workshops at her studio, providing her with free labor, and participants with hands-on instruction in the techniques. “Many of my friends and neighbors have participated in the building process. Michael (Smith) taught a great weekend workshop last August where people from all parts of the country came here and learned with us. Then this fall I was lucky enough to participate in the Mendocino High School’s week of sustainability workshops, so a few of the local kids got pretty excited about it and spread that to their families. Once you get to really play with earthen building you get hooked.”

Smith points out that Rocket Mass Heaters can be built into conventionally constructed homes, and they can also be built outside, no permit required. However fun they are to make, and there’s no doubt they are much better for the environment, but Rocket Mass Heaters are not for everyone. “It takes a certain special someone to be willing to build their own wood stove,” says Smith. “I like to compare it to owning an old Volkswagen. They can be inexpensive and efficient to run, but they can require a lot of tinkering.”

Mobert agrees with this. “The best way to make anything last is to live with it for while, and if it breaks, fix it,” says Mobert. “It’s called maintenance. We always expect everything to be maintenance-free, but unfortunately, that’s almost never the case.” At least with Natural Building and Rocket Mass Heaters, the chances are, since you had a hand in building it, you will know just how to fix it. Now that’s creative, local, and sustainable empowerment.