Christina's House: Earthship and Straw Bale in Taos, New Mexico by Becky Kemery
"At this time, constructing and operating buildings consumes more materials and energy than any other single activity in the United States." - from the Center for Resourceful Building Technology web site, www.crbt.org
(In the last issue of Alternatives we defined sustainable shelter and took a quick trip through some natural building methods. In this issue we'll take a closer look at Earthships and hear the story of Christina, who at 28 built her own combination Earthship and straw-bale home.)
In 1995, 26-year old Christina Sporrong moved from Seattle to Taos, New Mexico in search of sunny weather. Having experience in residential construction, Christina went to work for local architect and builder Mike Reynolds.
Earthships Mike Reynolds' buildings, known as Earthships, use earth-filled tires for the exterior walls and mortar-encased pop cans and glass bottles for interior walls. The tire walls are built into U-shaped rooms with the open side facing south. The walls are earth-bermed, which helps maintain a constant temperature in both winter and summer.
The south side of the Earthship uses large plate-glass windows set over indoor gardens to create a greenhouse. Winter sunlight warms the tire walls and earthen floor which then release the warmth during the night. This is the essence of passive solar building.
Reynolds has developed a model for shelter that approaches sustainability on every level. Not only are the walls made of recycled materials, but every internal system (heating and cooling, water and wastewater, power and waste disposal) has been designed to use resources wisely and to work as part of an integrated whole. For example, rainwater harvested from the roof is used for cleaning and bathing and is then channeled to planters inside and out. A solar toilet, which combines the principles of a composting toilet and a solar oven, reduces human waste to a handful of ash that can be used as compost.
When hearing about tire walls and belowground U-shaped rooms, perhaps you envision a dark, cave-like structure. Quite the contrary, Earthships are spacious and light-filled, and the combination of plants, tile counters and earthen floors makes these dwellings warm, inviting, and even luxurious. A friend from Oregon described an Earthship we visited in Taos as "the most beautiful house I've ever seen." My aunt Zena lives in an Earthship and says that the shape and feel of her home leave her feeling "embraced".
Christina's House Working on Earthships was an education for Christina. "It inspired me to build my own house and showed me that I could do it alternatively, cheaply and on my own. Mike gave me the tools to do that."
At a land auction in 1996 Christina purchased a quarter-acre of sagebrush-covered mesa for $500, and set about designing a house that she could build in one summer with the help of friends.
The house design took shape in two sections: one a belowground living and sleeping area and the other a ground level entry and kitchen with steps leading down to the Earthship room. Christina read up on straw-bale construction, visited local straw-bale homes, and decided to build with bales for her ground level room. "The trick", says Christina, "was to make the Earthship space larger than the front room in order to capture enough sunlight to be passive solar." Christina also decided to use a post and beam support for the roof instead of load bearing straw-bale walls.
Christina stopped working construction and picked up a job as a cocktail waitress so that she could build during the day and still earn money at night. In early spring, she went and staked out the area where her house would go.
The next step was to get tires from a local landfill and set them around the perimeter of her house-to-be. At this point Christina's life took on the rhythm that would last through the summer: work in the evenings to afford materials for the next part of the project, and work during the day digging out the Earthship floor and building courses of tire walls. Each wall tire had to be filled with earth and then tamped down with a sledgehammer. "It took about a half-hour to pound each tire. I could only do about 7-10 tires a day before I went to work—it was totally labor intensive. Even though this is a small Earthship, it still took over 100 tires, and that took a few months to build."
The first major project was concrete footings for the straw-bale walls. Christina built the forms and then called friends to help pour eight yards of concrete in one day. A month later she gathered materials for the post and beam framework, including posts recycled from an old feed store. Again she called together a crew and they put up the posts and beams. Next were the trusses and roof. Christina used Propanels, corrugated steel roofing with a baked-on ceramic coating which allows for safe rainwater catchment.
At last the tire-walls were finished and the straw-bale room became the focus. Christina purchased bales from a feed store. "A few were rotten and I had to buy some more. You only want to buy the bales when you're ready to put them up, so you don't risk getting moisture on them."
The straw bales were stacked in offset rows, like giant bricks, inside the post and beam framework. Rebar was driven top-down through the bales with a sledgehammer, and the walls were covered with chicken wire. "If I had it to do again," says Christina, "I would measure each bale prior to building, and then stack them in such a way that I wouldn't have to cut any bales. And I would use a weed whacker to clean up the walls before plastering. My bales were so uneven that, after the initial plastering, my place looked like a Smurf house. I had to use extra coats of plaster to even it out."
Finally the windows went in and Christina had a home. "I've taken my time on the finishing touches", says Christina, "like weather-stripping around the windows, insulating the ceiling and putting color on the walls."
Building Your Own Home "Alternative construction may be way more labor intensive," says Christina, "but it's worth it. It baffles me that people would choose to do traditional frame building, which is so unfriendly to the environment. Sustainable building expresses a different set of values, using materials that at some level are friendly to the environment."
Both of Christina's choices, recycled tires and straw bales, were environmentally sustainable. Straw is plentiful and is actually a waste product often burned in the fields rather than being harvested. The authors of Build It With Bales offer the following eye-opening perspective: "Using only one quarter of the straw available each year in North America, we could build over 3 million houses having an interior square footage of 1500 square feet"
If you're planning to build a sustainable shelter, you'll want to learn about different methods. Options (besides Earthships and straw-bale) include cob, cordwood, and earthbag construction. Each of these methods has its own web sites and books, hands-on workshops and skilled builders who can help (the resource list at the end of this article is a good place to start). It's a good idea to begin with reading and checking out the web sites, followed by taking a workshop or helping on a building project.
Once you begin designing your place, you may want to build a model or draw a floor plan. "The very first thing I did," Christina remembers, "was to build a miniature model of my design—it was a winter project. I remember using charcoal briquettes for the tires, and tying straw into tiny straw bales. I needed to build the model to visualize what I would be creating."
It's a good idea to check out your plans with a professional. An architect friend gave Christina input. "He said my design needed more windows," she remembers, "and had me change some things to make it more structurally sound.
Be sure to think through all the systems-not just the outer walls. Incorporate earth-friendly alternatives wherever you can (e.g., passive solar heating, solar power, greywater systems, etc.). There are resources that can help-books, organizations and builders willing to offer advice.
The Earthship is the most labor intensive of the sustainable building methods. Christina managed to finish hers because she kept it small, and her design simple, which I think is a good idea.
By designing small you will simplify your building process and may find your life "lightened" as well. Having lived on boats and in my van, I find I love the freedom that comes in living simply, the clear-headedness that happens when life isn't cluttered with big living spaces and lots of possessions.
Christina's success was due in part to combining long-term goals with daily planning sessions. Having set project goals like, "footing completed May 4th, post and beam by June 4th," she also organized herself on a daily basis. "Building the house", says Christina, "was like running my own construction job. Each day I'd start my morning by looking at what I had to do the following day and making a list (of people to have work with me, how many bags of cement to pick up, etc). Then I'd set about doing what I had planned (the day before) to accomplish that day.
Budgeting money and time is a challenge. It's easy to get caught up in details and fall behind on the basics. Remember that, as Christina points out, "once you are in your house, you can do the smaller projects on your own schedule. I built a stovepipe into my wall, and built the fireplace later. The trick is to realize what you can do with the resources you have so you don't wind up with an enchanting house but no financing for the roof. I've seen that happen." Christina also warns against buying all the materials in advance. "On my house there was no waste of materials, because I purchased as I went. I've seen people buy all their materials at the beginning and then not use half of them or have them get ruined."
Finally, use the people-resources all around you-to get ongoing advice, to help with building, or for professional input. You might want to hire someone with experience to help with part of the project. Whatever you decide, follow Christina's example: "I asked so many questions. I had to understand everything before I did it, and I picked up lots of tricks from others (like things to do so you don't have leaks in your roof). Even Mike came out once to see how the house was progressing and give me advice."
It takes enormous commitment to build a home. And, says Christina, "determination, pride, a strong ego, and craving a home space." The focus this kind of project takes is amazing. "I pretty much lived the house for an entire year. I was completely obsessed. I dreamt about it at night, then would wake up and make changes. It was a test of mettle, for sure, and it definitely made me stronger."
Hard Times and High Times There were some pretty discouraging times for Christina. Sometimes friends didn't show up to help; allergies to straw forced her to take antihistamines while building the straw-bale room. One story epitomizes the difficult times: "I ended up plastering the straw-bale walls in October," she reminisces. "There I was mixing sand and cement with the hoe outside and it started snowing. It took six wheelbarrows of plaster, wheeled in through the snow, to complete the job—and plastering is not easy. It was cold, my hands were frozen; I remember crying through the whole thing."
There are also highs, times to simply step back and admire the beauty of it all. "I remember one time I was sitting behind my house. The straw bales were up, there was a candle lit inside, and for the first time I really saw it and I said, 'Oh my gosh, how cool! I built this!' "
Designing and building a sustainable shelter for yourself is one of life's unforgettable journeys. In the end, the experience of building and the friendships that happen in the process may well be as important as the home you create. As Christina says, "Everyone is going to learn in their own way; everyone will approach building a house differently. The only guarantee is that there will be hard times, and there will be beautiful times and, in the end, it will change your life. I mean, what an achievement, to build your own house!"
Becky Kemery is a freelance writer focusing on sustainable building and yurts. She also supports herself as a tradeshow carpenter and cook. In October she took a week-long women's welding workshop in Toas with Christina, and attended a natural builder's colloquium in Kingston, New Mexico -"a totally inspiring month!" Becky would love to hear your sustainable building and yurt stories or questions. .
cover art © Leo Wyman