Sustainable structures: make the right choice for your new home.Sustainable construction involves assessment that includes considering the environmental, economic, and social aspects of the built environment. Factors that need to be addressed are energy efficiency, material selection, construction waste reduction, indoor air quality Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants. The IAQ may be compromised by microbial contaminants (mold, bacteria), chemicals (such as carbon monoxide, radon), allergens, or any mass or energy stressor and the general health and well being of the occupants, to name a few. The statistics coming out of the building sector are staggering. Energy efficiency becomes an economic concern given the Rocky Mountain Institute The Rocky Mountain Institute (RMI) is an organization in the United States dedicated to research, publication, consulting, and lecturing in the general field of sustainability, with a special focus on profitable innovations for energy and resource efficiency. estimate that $15 billion a year is wasted on heated and cooled air flowing out of leaky leak·y adj. leak·i·er, leak·i·est Permitting leaks or leakage: a leaky roof; a leaky defense system. Adj. 1. buildings. Material selection becomes an environmental concern when it is realized that the average 2000-square-foot home built in America requires approximately 1 acre of forest which equals about 44 trees. Approximately 1.5 million homes are being built a year, providing enough framing lumber lumber, term for timber that has been cut into boards for use as a building material. The major steps in producing lumber involve logging (the felling and preparation of timber for shipment to sawmills), sawing the logs into boards, grading the boards according to to stretch to the moon and back six times. Every year 136 million tons of construction waste is sent to the landfill, almost a ton per house. The social effects of buildings arise as a health concern with the estimate that Americans spend ninety percent of their time indoors. This number, coupled with the facts from the U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and : on average, indoor air is two to three times more polluted pol·lute tr.v. pol·lut·ed, pol·lut·ing, pol·lutes 1. To make unfit for or harmful to living things, especially by the addition of waste matter. See Synonyms at contaminate. 2. than outdoor air, which prompts an imperative to change the way we build. Issues surrounding energy efficiency have spawned the field of building science which studies how buildings interact with the elements. Controlling moisture, air infiltration infiltration /in·fil·tra·tion/ (in?fil-tra´shun) 1. the pathological diffusion or accumulation in a tissue or cells of substances not normal to it or in amounts in excess of the normal. 2. infiltrate (2). , and maintaining a continuous layer of insulation are a few of the considerations in this discipline. This field focuses on the construction of high performance buildings as well as improving existing structures. The emergence of this field has greatly improved the energy efficiency of construction by decreasing the economic burden of wasted energy we are bearing. It is also increasing the lives of our structures due to their protection from the elements. Concerns about the sustainability of construction materials have spawned movements such as certified See certification. wood programs, advanced methods of construction, and the resurgence in natural building. Certified wood programs require wood to be harvested in a manner that keeps the forest healthy and allows for continual growth for future generations. Sustainably harvested wood is becoming more available. Ask for Forest Stewardship Council The Forest Stewardship Council (FSC) is a non-profit organization based in Bonn, Germany. The Council's stated mission is "to promote environmentally appropriate, socially beneficial and economically viable management of the world's forests". (FSC FSC See: Foreign Sales Corporation ) certified wood (www.fscus.org). Some examples of advanced construction materials include structural insulated panels Structural insulated panels (or structural insulating panels), SIPs, are a composite building material. They consist of a sandwich of two layers of structural board with an insulating layer of foam in between. (SIPs), insulated in·su·late tr.v. in·su·lat·ed, in·su·lat·ing, in·su·lates 1. To cause to be in a detached or isolated position. See Synonyms at isolate. 2. concrete forms (ICFs), and autoclaved aerated aer·ate tr.v. aer·at·ed, aer·at·ing, aer·ates 1. To supply with air or expose to the circulation of air: aerate soil. 2. concrete. SIPs surround ridged insulation like styrofoam with oriented strand board Oriented strand board, or OSB, or waferboard, or Sterling board (UK), is an engineered wood product formed by layering strands (flakes) of wood in specific orientations. (OSB OSB abbr. Order of Saint Benedict ), a composite product which resembles plywood plywood, manufactured board composed of an odd number of thin sheets of wood glued together under pressure with grains of the successive layers at right angles. Laminated wood differs from plywood in that the grains of its sheets are parallel. . These units, which range from 4' X 8' to 8' X 24', are lifted by a crane, and placed on the foundation as a wall system and atop the roof as the sheathing and insulation. SIPs, if installed correctly, are extremely energy efficient and allow the project to be under roof in a fraction of the time compared to stick flame construction (www.sips.org). Insulated concrete forms are foam blocks that are stacked in a running bond which provide a permanent insulated form for concrete. Concrete is poured into these forms one floor at a time. ICF (Internet Connection Firewall) The built-in firewall in Windows XP. It provides a stateful inspection of packets which accepts only responses to requests originated by the user. construction provides the homeowner with an airtight air·tight adj. 1. Impermeable by air. 2. Having no weak points; sound: an airtight excuse. airtight Adjective 1. , solid home that is highly insulated (www.icfweb.com) There are at least twenty other advanced construction methods on the market. Some other examples are an energy efficient log home (www.enertia.com) pre-cast concrete walls that are brought in on a crane (www.superiorwalls.com), and geodesic domes geodesic dome (jē'ədĕs`ĭk, –dē`sĭk), structure that roughly approximates a hemisphere. Popular in recent years as economical, easily erected buildings, geodesic domes are geometrically determined from a model and may , the creation of the inventor Buckminster Fuller. Many of these methods of construction are comparably priced to stick frame construction and use less wood than conventional forms of construction while providing other benefits wood buildings cannot. One of the most effective methods of reducing the impact structures have on our natural resources is building appropriately sized structures. Oversized o·ver·size n. 1. A size that is larger than usual. 2. An oversize article or object. adj. o·ver·size also o·ver·sized Larger in size than usual or necessary. residential homes are a chronic problem in the U.S. and have been termed McMansions by Sarah Susanka Sarah Susanka (born c. 1957) is an England-born American architect and author. Susanka is a proponent of the "Not So Big" philosophy of residential architecture, which aims to "build better, not bigger". author of The Not So Big House. Natural building has seen a renaissance in the US. Some consider building with natural, minimally processed materials to be the epitome of sustainable building. Others like it because it can be owner-builder friendly. Older ways of building such as cob and adobe are being rediscovered, while cordwood cord·wood n. 1. Wood cut and piled in cords. 2. Wood sold by the cord. Noun 1. cordwood - firewood cut and stacked in cords; wood sold by the cord and straw bale A straw bale is a bundle of straw tightly bound with twine or wire. Bales may be square, rectangular, or round, depending on the type of baler used. When bales are used to build or insulate buildings, the straw bales are commonly finished with plaster. construction are reaching maturity and are being refined. Cob uses soil mixed with straw and sand to make "loaves loaves n. Plural of loaf1. loaves Noun the plural of loaf1 loaves loaf " that are stacked for a wall. Cordwood masonry masonry: see brick; concrete; stonework; tile. masonry Craft of building in stone, brick, or block. By 4000 BC, Egypt had developed an elaborate cut-stone technique. is done using firewood sized logs as bricks, with the ends facing inside. As one of the most publicized pub·li·cize tr.v. pub·li·cized, pub·li·ciz·ing, pub·li·ciz·es To give publicity to. Adj. 1. publicized - made known; especially made widely known publicised natural building methods, straw bale construction is becoming more popular by being covered on Home and Garden television and Natural Home magazine to name a few. Waste is a big concern when it comes to construction (look at the dumpster on any construction site). One way to address construction waste is through the waste reduction requirement of the many statewide green building programs such as Earthcraft House EarthCraft House is a green building program created in 1999 as a partnership between the Greater Atlanta Home Builders Association and Southface Energy Institute that teaches builders the latest methods of resource and energy-efficient construction. in Georgia, Built Green in Colorado, and the newly developed NC HealthyBuilt Homes. Reducing waste lessens the impact that construction has on our landfills and our natural resources. Reduction in waste can largely be achieved by planning the use of resources and recycling recycling, the process of recovering and reusing waste products—from household use, manufacturing, agriculture, and business—and thereby reducing their burden on the environment. or donating what cannot be utilized. Green building programs recognize this practice as a contribution towards sustainability by awarding points for recycling/donating construction materials. These points in turn assist homeowners in achieving certification under their state green building program (http://www.ncsc. ncsu.edu/programs/NCGBPChecklist.pdf) Americans spend ninety percent of time indoors, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. the Worldwatch Institute The Worldwatch Institute is a globally-focused environmental research organization. Based in Washington, D.C., the institute was founded in 1974 by Lester Brown. Christopher Flavin is the current president. . Indoor air quality, access to daylight, and accessibility are just a few of the concerns. Indoor air quality is a concern given the massive amounts of chemicals used in the construction industry that can adversely affect our health. Access to daylight is often a rarity in buildings, yet is proven to dramatically increase productivity in schools and businesses. Ensuring the health and well being of all a building's occupants is of paramount concern when implementing sustainability. Accessibility for the physically disabled is required by law for all commercial and state buildings. However, these standards are not always extended to the residential market. Accessibility involves keeping primary rooms on the ground level, keeping doorways three feet wide or greater, having wheelchair accessible bathrooms and showers, having door pulls and handles that are easy to operate, and turnaround space for wheelchairs in all rooms. These adaptations allow a home to be accessed by the physically disabled as well as the elderly. A house designed in this way implements a practice termed universal design and is responsive to the physical demands and challenges of life. Sustainable construction is a rapidly emerging and vast field of study. Changes in our environment caused by buildings, and the effects on our health that living in them cause have alerted us to a broad problem. We have to find a better way to build. The answer is not one building method or design. The answer is in the diversity of building methods that we currently have, sustainable assessment of each, and the ability to always make them better. Marcus Renner is co-founder and manager of Appropriate Building Solutions, Inc., a sustainable construction company in Asheville, NC: abs@buildsustainable.com, www.buildsustainable.com or 828-350-0451.
SUSTAINABLE BUILDING COMPARISON TABLE
Compare and contrast these methods and structure types to find your
favorite.
Table created by Marcus Renner.
Building Expense Construction Energy Owner
Method/Type Time Efficiency Build-
ability
Wood Low Normal Usually Low
Framing poor
Steel Low Normal Poor Low
Framing
Log Homes High Fast Poor Low
Insulated 1-5%+ Fast Very Low
Concrete more good
Forms
Structural 1-5%+ Fast Very Low
Insulated more good
Panels
Autoclaved 10%+ Fast Good Low
Aerated more
Concrete
Geodesic Medium Normal Can be Medium
Domes poor
Timber High Fast Very Low
Frame good
Modular Low Fast Poor N/A
homes
Cast Off-site Low Fast Good Low
Concrete
EZ Block Medium Fast Good Low
Cellular
Concrete
Block
Straw Bale Medium Fast Very High
good
Cob Low Slow Good High
Rammed High Slow Good Low
Earth
Concrete High Fast Very Low
Domes good
Double High Slow Very Low
Masonry good
Earthship Low Slow Very High
good
Underground Medium Normal Very Low
Homes good
Papercrete Low Fast Good High
Earth Bag Low Slow Good High
Cordwood Low Fast Good High
Slipstraw Low Slow Good High
Stone High Normal Poor Low
Adobe high Slow Good High
Yurts Low Fast, Poor High
Building Thermal Air Design Embodied
Method/Type Mass Infiltration Limitations Energy
Wood No Can be Usually right Low
Framing high angle
Steel No Can be " High
Framing high
Log Homes No Can be " Low
high
Insulated Yes Low " High
Concrete
Forms
Structural Yes Low " High
Insulated
Panels
Autoclaved Yes Low " High
Aerated
Concrete
Geodesic No High Circular Low
Domes
Timber No Low Usually right Low
Frame angle
Modular No Can be " Low
homes high
Cast Off-site Yes Low " High
Concrete
EZ Block Yes Low Right angles High
Cellular
Concrete
Block
Straw Bale No Low Angled or Law
curves
Cob Yes Low Unlimited Low
Rammed Yes Low Curves Low
Earth possible
Concrete Yes Low Rounded High
Domes
Double Yes Low Usually right High
Masonry anqle
Earthship Yes Low Curves Low
possible
Underground Yes Low Curves High
Homes possible
Papercrete Yes Low Unlimited Low
Earth Bag Yes Low Unlimited Low
Cordwood Yes Low Curves Low
possible
Slipstraw Yes Low Curves Low
possible
Stone Yes Low Unlimited Low
Adobe Yes Low Curves Low
possible
Yurts No High Usually Low
round
Building Recyclablity Local
Method/Type Production
of material
Wood Reuse No
Framing
Steel Must be No
Framing processed
Log Homes Reuse or No
milled
smaller
Insulated
Concrete No No
Forms
Structural
Insulated No Yes,
Panels polyureth
one type
Autoclaved
Aerated Rubble No
Concrete
Geodesic
Domes No No
Timber
Frame Reused or Yes
milled
Modular
homes Reuse No
Cast Off-site
Concrete No Yes
EZ Block
Cellular Rubble Yes
Concrete
Block
Straw Bale Reuse or Yes
compose
Cob Returns to Yes
original
Rammed Return to Yes
Earth original
Concrete
Domes No Yes
Double Rubble Yes
Masonry
Earthship No Yes
Underground No Yes
Homes
Papercrete No Yes
Earth Bag Return to Yes
original
Cordwood Reuse the Yes
wood
Slipstraw Return to Yes
original
Stone Reuse Yes
Adobe Return to Yes
original
Yurts Reuse Yes
Myrick Rozier is completing her Master's degree master's degree n. An academic degree conferred by a college or university upon those who complete at least one year of prescribed study beyond the bachelor's degree. Noun 1. in industrial Technology and Building Science at Appalachian State University History Appalachian State University began in the summer of 1899 when a group of citizens of Watauga County, NC, under the leadership of D.D. Dougherty and B.B. Dougherty, began a movement to establish a good school in Boone, NC. Land was donated by D.B. in Boone, NC. |
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