How we choose to live makes up a big part of us going
green; whether we recycle, use energy efficient light
cork flooring or support sustainable eco-friendly farming,
every component that we choose to commit to adds up to
make a huge difference for our earth and our own
lives. But what about where we live those
lives? The greatest portion of our lives are spent in
the dwellings we call home, so it isn't so much of a
surprise that a good portion of the carbon output the
world over, comes from those same domestic dwellings.
On top of being generally inefficient, the majority of
modern spec style homes are creating more and more
living environments that are devoid of individuality.
Luckily, there's a sprawling variety of building styles in the eco-friendly home movement, allowing the home owners to express exactly what they feel concerning their personal living environment; and also allowing them to keep their goal of minimal impact on the eco-system a heavy priority. The importance of how our living space effects how we feel from day to day, often gets brushed under the rug. From every level of perception, our home can shape our state of mind and our health, from how the walls are situated, to the color the are painted, to the fumes we inhale because of that paint. What's so awesome is that since where we live is going to shape us on a psychological and physiological level, it very well may be the most proactive, external tool we have toward achieving a state of genuine well being.
Let's begin with a blank slate and approach the process from the point of view of a home builder at square one. What kind of house do you want? Options are the least of your worries when it comes to choosing an eco friendly home. The styles range from conventional suburban with complete solar power capacity, to freeform organic with full functioning off-grid independence. The possibilities are only limited by your own imagination, since you can incorporate any of the eco-elements that you are the most passionate about with a synthesis of your favorite design styles. How about a passive solar heated Mediterranean inspired cast earth home with an internal courtyard that helps to filter air and feeds off of your grey water drain off? Or, imagine your very own sleek and contemporary modular home on the seashore - complete with a solar roof, recycled material construction, and a deceivingly low price tag to match! You get the idea. It's mix and match at its best! So how 'bout I get down to describing the oh-so-green parts of this earth and eco-friendly home building equation!
In the beginning, there was Cobb
In the beginning....there was Cob...and Adobe, but we'll get to that later. If you're like me and you heard this term for the first time and had an image in your head of a building made of corn cobs and mortar (something like a picnic themed log cabin), you'd be wrong. Cob is one of the very oldest earthen styles of home building. It utilizes a mixture of clay, sand and straw that is capable of being extremely freeform in construction. This is due to its system of applying the earthen mixture - not in bricks - but in big, organically shaped globs - or as they called them back in the day - "Cobs". These "Cobs" would eventually dry to form thick insulating walls due to the straw pieces within the earthen mixture. This component - cob's insulating properties - is what makes this particular form of building better suited for extreme weather. The English and Irish countryside are dotted with cob structures that remain standing and inhabitable after hundreds of years, thus testifying to the endurance and validity of these resourceful straw and earthen dwellings.
The internal walls of cob structures are often made with a cob variant named "light clay", which is mostly straw tossed in a clay slip, much like romaine in a Caesar salad dressing. This material requires a timber frame because it's not load bearing, but is highly insulating and very useful for keeping internal rooms cozy through a cold, Celtic winter. Cob can be shaped to portray any type of architecture that your imagination can project, though the most prevalent examples of cob are in the "countryside cottage" style with thick sloping thatched roofs, green painted wooden doors and shutters, with the cob itself whitewashed and rough in texture. Incredibly charming and incredibly practical and earth friendly.
Okay, so back to the beginning again...Adobe makes up some of the very oldest recorded structures in the world. We're talking millennia here folks. The thriving Egyptian civilization depended on these trustworthy clay, sand and water bricks. With their seemingly inexhaustible supply of materials, and adobe's perfect fit in a warm, arid climate, the Egyptians built an empire out of this early match made in...uhm, earth. The adobe bricks are mixed within their molds and allowed to dry in the sun before being stacked on top of one another. Aesthetically, adobe can also be used to plaster the outside of the bricks to create a smooth surface, or as flooring that is then buffed and cured with natural oil. The major pro of adobe is its wonderful ability to retain heat and release it very slowly, thereby keeping homes colder in the day and gently warming them during cooler nights.
Have questions on the longevity of a house made out of dirt? Well, just take a look at none other than the Great Wall of China. That's right, the most impressive piece of architecture built by man is made from rammed earth. Rammed is constructed in pretty much the way it's name describes. The downside to this process for some is its use of heavy mechanized equipment in most cases. But the upside is a stunning, layered pattern in the sediment that occurs and can give any home a unique and organically occurring artistic touch. Also, rammed earth homes tend to have a very solid and peaceful air in its interior while also providing passive solar heating and cooling properties. It is recommended that an insulation is applied for climates with more extreme cool temperatures. The process consists of a frame being built with approximately 18" to 24" in fill width and then the earthen mix being compacted with a pneumatic process.
Poured earth offers many of the similar benefits as concrete. It is easily mixed and transported in much the same way ordinary concrete is. The primary difference lies in that instead of using sand or gravel, poured earth uses specific soil types. This difference gives poured earth a much more organic and natural feeling that still offers all of the passive heating and cooling benefits. One added benefit is the materials highly resistant nature toward the elements, so it ends up being a much wiser choice for areas prone to inclement weather. Poured earth's ability to...well, be poured, also allows you to have a steel insulating grid in place within the wall, which helps with the structure's thermal mass and general strength. Granted, with pluses like low maintenance, conservation of materials, and fast construction, it is no surprise that cost could end up being anywhere between 10% to 20% more than standard home building. But, with growth in the demand, prices are expected to wane.
Cast earth may very well be the best of both worlds of all the earthen structure options. Developed by a chemist who longed to create an easier and more accessible version of the adobe home he grew up in in Arizona. He wanted to take a process that, in the past, had been painstakingly labor and time intensive and put it in hyper speed by being able to cast set the earthen mixture instead of slow-forming individual bricks or compress bit by bit. His answer came in the form of an earthen mixture complemented by a Plaster of Paris that has been treated with a retardant in order to delay the setting process for up to eight hours, thereby making larger scale projects possible. Cast Earth is also much more forgiving when it comes to the variety of soil able to be used, plus it even has a greater tinsel strength than that of adobe and rammed earth. Another helpful plus is that cast earth is less likely to crack, since it expands while setting, as opposed to shrinking. The organic designs that result from pouring cast earth are also an attractive consideration, not to mention that within only one day your walls would be poured and setting - ideal for time sensitive projects. As for thermal mass, cast earth is right up there. And for added insulation needs, an internal layer of insulation is easily incorporated into the wall's width before the earthen plaster mixture is poured.
It sounds a little bit like a space aged putdown, but Earthbag is truly a form of sustainable construction. The idea is simple enough...it's a house made of bags...full of earth. It also happens to be extremely strong, insulating and expensive. Back in the day, burlap was the bag of choice, but now long polypropylene bags ensure a long lasting earth holding material. First, a tranvh is dug as foundation, then earth bag filled and layered in place using barbwire as an interbag stabilizer. A coat of plaster, shot, or papercrete finish and protect the outside of the bags, giving the homes a lovely adobe-like appeal with gorgeous curves and arches detailing the structure. Since Nadar Khalili at the Cal-Earth Institute began experimenting with Earthbag's potential, interest in this eco-minded technique has grown exponentially.
The number one reason most home builders end up going with a type of strawbale construction is its superior insulating properties, plus the fact that straw is an extremely sustainable and renewable resource. The only hindrance is that most areas that allow for strawbale within their building code will only allow for post and beam style building with strawbale as insulation. Still a wonderful alternative, this technique, however, will only save about 15% of the lumber that would be needed in building a tradtional house. Structurally using post and beam is the safe route given that when strawbales are used for all the load bearing there could be potential shifting once the bale has been compressed under weight. The cost ends up exceeding that of a traditional house once custom labor is thrown in , like the plastering of all the walls. It is a good idea to cover the bales with a breathable and durable material and not something that would be a complete moisture barrier that may eventually cause condensation and then rotting of the straw. This is also why strawbale has become extremely popular in the dry desert southwestern states.
Earthships were created by former architect, now biotech, Michael Reynolds in response to the litter crisis that took place in the 1970's. He focused on designing structures that were built using recycled materials and completely self sustainable. He incorporated passive solar heating and cooling, solar power panels, the recycling of grey water, rain water collection, waste composting, indoor gardens and much more. What started out as humble brainchild has grown to whole communities prescribing to the earthship design. The expressive nature of the earthship attracts a lot of people, and the complete off-grid nature of the structures seal the deal in the end. Over the years, the design has become more efficient and has worked out some of the original kinks from the early 80's. Reynold's Taos, New Mexico based Biotech business has made several options for construction, from hybrid earthships, modular, or completely custom.
Cordwood is, in a way, the cooler wooded regions answer to the southwest's adobe. Using easily available scrap wood and Portland cement, this style of building is highly resilient and offers both thermal mass and excellent insulation. Cordwood also makes a lot of sense for an eco friendly home builder living in an area like Washington or the Smoky Mountains where scrap, firewood sized pieces of lumber are in abundance and considered waste for the most part. As opposed to a desert climate, where dirt is vast and easy to find, and wood is much more scarce, adobe ends up being a much better choice for those regions. Cordwood also has a charming appearance that only requires an outer clear seal, as opposed to strawbale, which needs full plastering over. Cordwood is also probably the easiest and the least skill demanding technique and probably the best for inclement and cold, snowy weather.
Also one of the most ancient forms of building, rock homes can be some of the most beautiful and enduring around. Rocks can either be dry stacked or mortared with cement and offer excellent thermal mass. The act of building with rock is an extremely Zen and vision driven talent as the builder creates and solves the puzzle before them. It is needed to insulate and plaster the interior walls of the rock in order to maintain the internal temperature of the home. There is also an undeniable feeling of security and being grounded when inside a rock home.
To sum it all up, there are endless possibilities on how one can incorporate eco friendly home design into their next home. You can piece together aspects of all your favorite and build an eco-hybrid home. Or, you can go with easy and affordable eco minded modules. Even a shot-crete dome home could be just what your eco dreams are leading you to, not to mention a standard home, simply built to LEEDS certification and full of green appliances and features. So, have fun and let your dreams be your blueprint!
Interested in learning about what else you can do to turn your home into a greener eco-friendly home...inside and out? Then catch up with our Green Home Tips below...