Autoclaved Aerated Concrete (AAC) is a pre-cast block or panel that is used for walls roofs and lintels (weight bearing structure over doors and windows). It is a good green building material because it has low manufacturing impact, is recyclable, does not off gas toxic fumes, is extremely durable and saves energy by having superior insulating properties. It provides water fire and sound resistance, and insect protection. AAC is made of a mixture of natural raw materials (lime, cement, water, sand) expanded to foam bubbles and then heated under steam and pressure of an autoclave. It has been used in Europe for 80 years and recently in the Methow Valley. Very intriguing. www.aacpa.org
Wood is a carbon banking, renewable resource and a healthy building material, if used with understanding. By that we mean, when possible, it is resource conserving to reuse old lumber and secure lumber from certified forests (local as possible, of course). And it is safer for you and the environment to finish the wood with non-toxic products. See www.twispenvironmental.com. Advanced framing is an engineering technique to reduce the amount of wood needed to build a house. This idea has been around for a while, but has recently been revived and updated. The typical technique is to use 2 x 6 studs, 24 inches on center, for exterior walls. This makes a stronger wall, is quicker to build, and provides more room for insulation. There is less thermal bridging i.e., the wall has less places where heat can escape or get in. At the very least, ask your builder if they know about this.
Reuse, Self Sufficient, Indigenous Materials…three goals of an Earthship. Reuse: old tires packed with dirt to make strong, quiet, earth sheltered, thermal mass walls, aluminum cans (covered with plaster) to make indoor non load bearing walls. Indigenous Materials: dirt from the site, tires from local area, etc. Self Sufficient: An Earthship can use grey water, black water and rainwater systems. They use internal food and plant growing, solar and wind power systems. Combining all these systems in the home is known as biotecture. Earthships were first designed by Michael Reynolds in New Mexico, but are built all over the world now. We have a number of Earthships in the valley. www.earthship.net
Mikey Blocks:
Mikey Blocks are an insulated concrete form (ICF) block made exclusively of expanded polystyrene foam (EPS). EPS is made by adding a gaseous blowing agent with heat in the form of steam, which expands the solid material into foam. EPS is a highly insulating material because of the air trapped in it. The blocks are 4 foot long and only 3.5 pounds each. The 4 ft. block lengths are easily cut into pieces for all spaces and produce almost no waste. They are light enough for one person to build the walls of a house and have minimal equipment needs. Concrete is poured down a hole like other ICF systems to make the building strong while using a lot less concrete than traditional masonry techniques. The house can go up very quickly. Patrick Hannigan, a local builder, made a 1200 sq. ft. house out of Mikey Blocks.
Pre-engineered Panelized Wood Frame Systems:
This is a variation on the idea of prefab, where a house is assembled in the factory and shipped to the site. With this idea, the walls, roof trusses, floor systems, etc. are made efficiently in the factory, shipped as separate pieces and assembled on the site. The accuracy of pre-engineering provides a high quality, airtight building envelope and almost no waste of lumber. Designing for energy efficiency can happen at the factory using advanced engineering knowledge. The labor time is shortened and construction problems minimized. Paul Smith built his own panelized wood home in Winthrop, from the Winton Global Company. The company mills their own lumber, and they are committed to environmental forestry practices. Paul is a distributor for the company. You can use one of their pre-designed homes or have a custom one built. Paul’s home has a beautiful stucco finish, built for a fire prone land. Contact Paul Smith 509-996-3945 or paulsmith@methownet.com
Rammed Earth:
If you have the proper soil mixture of clay and sand on your site, you can build with little impact. What resource is more abundant and close by than dirt? Rammed earth walls are strong enough to carry the ceiling (load bearing). There are many soil oriented natural building techniques in use today, and rammed earth is one of the most elegant. However, it is very labor intensive and costly, if you do not build it yourself. Some of the oldest buildings still standing, are made from rammed earth. The soil mixture, with a stabilizer, is poured into reusable wooden wall forms of great thickness in layers of about 12 inches and compressed by hand or a pneumatic tamper. The walls do not have to be finished or coated with any material and are maintenance free. The “breathing” walls regulate the moisture in the air by absorbing excess water and releasing it to make a healthy and comfortable indoor environment. The wall thickness keeps the home cooler in the summer and warmer in the winter. This thick wall flywheel effect slows the movement of air. There is a company that adds a layer of foam in the center of the earthen walls to add insulation This helps control the amount of cold or heat coming through the walls. Coupled with the flywheel effect of slowing down the flow of air, this can save a lot of heating and cooling energy. There are a rammed earth houses in the Methow.see www.sirewall.com
Rastra is a widely used insulated concrete form (ICF) system, made of varying size blocks consisting of a mixture of concrete and over 80% post consumer waste (Styrofoam pellets etc.). Rastra is used for used for walls, roofs, and other house parts. The blocks use small amounts of concrete in their manufacture, and have holes in the middle that when stacked together are filled with concrete and rebar to build strength while still being stingy with concrete. Cement is one of the more energy intensive and toxic byproduct producing materials, and the most common material in building construction. Just two concrete plants in Seattle release about 12% of the cities annual green house gases and release mercury, dioxins etc. Rastra provides insulation, thermal mass, air tightness, sound attenuation, mold and insect resistance as well as strong walls and roofs. Gary Phillips has used Rastra in many beautiful valley homes, matching its’ ability to make strong walls well, with the load requirements of earth berming. see www.gp-designs.com
Straw bales are an agricultural waste product, usually sourced locally and stacked like bricks to build either load or non-load bearing walls that insulate exceptionally well. Straw bales are a rapidly renewable resource. Because straw is no longer alive, it does not attract creatures that need food and does not provide oxygen (so it is fire resistant). A properly designed and detailed straw bale home can out perform conventional stick frame style houses. In the wet climate of England, straw bale homes have stood for hundreds of years. Straw bale homes are some of the most widely built. Many straw bale homes have been built in the Methow. Architect Kelly Lerner has designed, with the owners, an interesting straw bale home.--- she is at www.one-world-design.com, also see: www.thelaststraw.org
Geodesic Dome:
Geodesic domes are some of the more popular energy efficient alternative homes built today. The dome idea was not originated, but developed and popularized by Buckminster Fuller in the 1950’s and 60’s. In the current building environment, geodesic domes are used in large commercial structures as well as individual homes. A geodesic dome is described as great circles (geodesics) lying on the surface of a sphere that intersect to form triangular elements, which adds rigidity and spreads the stress across the entire surface of the structure, (see: Wikipedia, Geodesic Domes). Often the dome is made with triangular wood forms attached to each other. The resulting form contains the greatest volume for the least amount of surface area. Dome homes are very efficient to heat and need fewer materials to build. Like all home building techniques, domes must be made properly to effect energy efficiencies and structural stability. The last years have brought many innovative solutions to the building challenges of geodesic domes. See: www.aidomes.com, Dome homes are visible in the valley.
Cordwood Masonry:
A simple definition: “cordwood masonry is an old building technique where by walls are constructed of short logs (log ends) laid up widthwise in the wall with a special mortar matrix."—Rob Roy. The finished walls show log ends as a major design detail. If constructed and detailed properly, cordwood homes use both insulation (keep heat or cold in or out) and thermal mass (slow the movement of heat or cold coming through) to great effect. They can be super energy efficient. Like many natural building techniques, cordwood is easy enough for the non-professional builder to make. www.cordwoodmasonry.com
Yurt:
Yurts began as nomadic homes in Central Asia. Like Indian teepees, they are strong, quick to build, and quick to disassemble. A yurt is a round tent like shape which uses tension and compression to achieve stability and wind resistance. They are usually built on a deck or platform of wood, so impact to the immediate environment is minimal. They are economical to build and live in. During the past 40 years, the yurt idea has been adapted and updated to meet the demands of modern life. One company, www.smilingwoods.com, builds beautiful wooden walled yurts in the Methow Valley and beyond. People report that living in a round Yurt brings a feeling of peace and harmony. This is a good way to live lightly on the land.
Slipform Masonry:
Slipform techniques were first developed to construct the massive United States federal road system in the 1950's. It was a way to pour concrete in a fast and seamless manner by using a form (frame) that would be filled with concrete and then slid onward to be filled again before the first part was completely set. Slipform masonry uses wooden forms to accomplish the same end when building a structure. It is sometimes called 'cast in place concrete' or 'continuous concrete'.
Thomas J. Elpel has developed a way to use slipform ideas for owner built stone houses. He put beadwall panels with OSB on the inside house wall to provide insulation and structure to apply outside wall stones to. Many are taking up his ideas with great success. He teaches classes, sells a DVD, and has written many magazine articles and books. A recommended book of his is: Living Homes—Integrated Design and Construction. His web site is www.hollowtop.com.
"Slipforming makes stone work easy, even for the novice." Thomas J. Elpel.
Thanks to Laverne for this information.
