A group of conferring students engages around an earth-toned bench lounging in the cooling shade. A meandering earthen wall guides the eye toward the straw bale dormitory and two acre garden stretching below and to the south. A stilted cupcake blends into the forest along the garden perimeter which, on closer examination, reveals itself as a ten foot in diameter yurt made with bamboo and baling twine containing a reciprocal roof and walls that lean slightly toward the outside. After navigating the lower shallow-pond, whose future as a building material provider is anticipated in the growing cattails and hollow rushes, you discover two cousins sitting beneath a stand of open-grown fir. Both are tiny demonstration homes – models of vernacular architecture for the Pacific Northwest. They stand on stone and block foundations, supported by square and round-pole timber frames wrapped in a blanket of straw and clay. The round-pole rafters of one radiate up and around forming an ascending spiral culminating in a hand-split cedar shake roof and dome. The sculpted earthen pillars and walls are finished in clay and lime plasters joining three feet from the ground in a lazy wave. The insides host earthen floors and high mass heating stoves creating an energy efficient combination for indoor temperature control.
Most likely, if you are actually taking this tour of Aprovecho’s natural building work, you will also see a group (sometimes just one or two) moving amongst these structures: adding to them, caring for them and learning with them. Aprovecho’s campus is a campus built and, often designed, by students. It is a collaboration of guidance from experienced teachers with the enthusiasm and hunger of those who wish to engage in the built environment in a sustainable way. It is a collaboration made possible by the growing demand for the knowledge associated with natural building.
The Pacific Northwest has increasingly embraced the use of traditional natural building techniques in the home as evidenced by a growing presence in statewide building codes. For example, in Oregon one is now able to legally insulate using a technique called Light Clay Straw, which is a mixture of clay slip (watery clay) and straw packed into removable wall forms and typically finished with an earthen or lime plaster. This technique not only provides adequate insulation, fire-resistance, mold-resistance, and rodent-resistance but supports local rural economies by using an agriculturally based building material. In Oregon one is now able to legally incorporate timber and round-pole framing, straw bale wall systems, light clay straw, clay and lime-based plasters, earthen floors, living roofs, and grey water systems into one’s home.
Why then, do we not see natural building techniques more widely embraced by the general public? If there are building options available supported by state building codes, that reduce the amount of embedded energy in buildings, and that support rural communities through the use of locally-produced materials, why are we not seeing rapid adoption and support from state governments and the public? Aprovecho has identified three obstacles to the spread of natural building into the general public and is currently identifying partners and projects to potentially ameliorate these challenges. A brief description follows.
Public education jumps out as a major hurdle for the adoption of any new pattern or behavior within a culture. Most homeowners do not know what options are available and most builders do not know the full extent of what they are able to offer their clients. Aprovecho is doing its small part to ameliorate this challenge by opening up its campus to thousands of visitors every year giving them a chance to see natural building up close. Many visitors are surprised to witness how seamlessly and clean an earthen plaster finishes an interior space while simultaneously hearing about its health and energy performance benefits. Aprovecho is also training dozens of new and experienced builders, most notably during our annual Sustainable Shelter Series, every year, empowering participants with the knowledge and skills to either build their own home or, for contractors, the ability to offer new and diverse services to their clients.
We still do not know enough about the materials we are using and have yet to explore the full extent of the materials we could use. In order to responsibly develop new techniques and give both governments and homebuilders confidence in their performance, we need clear measurements for R-value (including the advantages of high mass,) vapor permeability and absorption capacity, durability and economic impact. Good information exists for some natural building assemblies but in order to encourage more widespread adoption we need to extend and deepen these studies.
Though natural building materials are comparatively inexpensive when compared to conventional materials, labor costs are typically much higher. Often this is because the natural materials being used are mixed by hand which is a slow process. What is currently needed in the natural building movement are the labor saving technologies and building systems that will allow building contractors to offer natural building assemblies at a competitive price. Aprovecho is currently in the process of identifying partners and supporters for a research project dedicated to producing and open-source publishing three of these labor saving technologies. If you are interested in hearing more about this project or any of Aprovecho’s other natural building initiatives as a builder, client, supporter or student please contact Chris Foraker at firstname.lastname@example.org or visit the Natural Building program on the website at www.aprovecho.net.