Eco comes from the Greek word "Oikos" meaning house, habitat or environment in relation to ecology.
When we place these two words together in the form of Eco-culture we have a resurgence of a character, a new generation that is attempting to integrate the relationship of science concerned with organisms and their environment with a society of people. This renewed awareness stems from a grave desire for change, in an attempt to right the wrongs of conventional habits and behaviors addressing ecology of design to maintain a healthy planet. The characteristics of this eco-culture wherever feasible choose to use renewable energy sources. They believe that ecology and economics have a life-cycle of embodied energy and the costs include the environmental impacts of technology and the externalities as a result thereof. Conventional cultures live in short-term options, they tend to have little regard for global cultures, and destroy local commonalties. Eco-culture respects the traditional knowledge of existence and supports local materials and biodiversity (Candise Gossen “Adobe, Rammed Earth and Wood: An Energy-Based Environmental Analysis of Residential Construction in Phoenix, Arizona” May 1993). .
Ecological designers seek to mimic the function of ecological systems and to incorporate them into human society a new social paradigm is emerging human social ecology. Humans are creatures of habit and our behavior is a reflection upon that style of thinking that is currently creating more destruction and waste by-products such as pollution than our earth can regenerate into its life cycle. Eco-culture is perhaps our new paradigm to an immediate needed change. Current building practices make extensive use of finite organic resources and this cannot continue indefinitely. Alternative methods of building construction and materials to create will to increasingly be considered.
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Many building sites are first cleared and leveled before construction, so that any and all natural inhabitants of the site, including plants and animals, are destroyed or severely disrupted. Ornamental landscaping then follows construction, often with manicured grass and non-native species that require watering and chemical fertilizers.
Alternately, buildings can enter into the landscape they inhabit, instead of disrupting and replacing it. Careful site design can identify features, trees and habitats that should be protected and preserved. Contractors can then clear only the land required, and build the house among the existing natural features.
Construction = 11% of the total energy consumed in the United States annually the equivalent energy value of 1 ¼ billion barrels of oil
Of this 11% half of this new building construction, with single family homes the top new construction activity
90% of new single-family dwellings built consist of wood frame construction even in areas where this from an ecological perspective makes little sense such as Phoenix Arizona where there are few trees. .
The process of understanding the ecological and energy consumption associated with these processes is called an environmental life cycle analysis.
Energy efficiency: minimize the amount of energy consumed to keep a building powered, and comfortable
Embodied energy: goes beyond energy efficiency to examine the direct and indirect processes of extraction, transportation, construction and operation of each structure that is built during the full life cycle of not only the building but also examines all the processes involved in assembling and then dismantling that product or service
Ecological footprint: look at the total impact of human activities on the ecology of the earth to develop an understanding of how we affect the natural world around us
A Life Cycle Analysis of the Embodied Energy Involved in the Production of Lumber
Candise Gossen says, “Each object has a cycle called a "Life-cycle". It has a beginning, an ending, and a new beginning. Energy as matter is only transformed, it can never be rid of. The life cycle of an object, such as a piece of lumber for example begins with a tree. In its natural surroundings the tree grows supporting its needs and wastes and until we modify its environment, the tree continually sustains its ecosystem.”
Extraction Take for example a life cycle analysis of timber. Once arrived at the distributor, the lumber is further divided and shipped again by truck to a local retail supplier. At this point the consumer purchases the materials and again ships them to the building site. Upon reaching the site, the material which was once a simple element, a tree, is now an extremely complex building material that has been transported several hundreds if not thousands of miles away from its home. It has been stripped, cut, bonded, shaped, treated and is now being used in the construction phase of the building project to make a shelter.
Transport including all vehicles, rail and truck and their consumption of fossil fuels.
Construction It is during this construction phase that multiple layers of wood products bonded with adhesives and formaldehydes are sealed, painted and encased with more adhesives, solvents and chemicals to complete the shelter. Diesel is needed for on site machinery and when electric is needed coal or natural gas is needed to generate it. Then there is the transport of workers and materials. These processes associated with the construction of the building itself accounts for around 15% of the total amount of embodied energy in the building.
Maintenance The constructed shelter stands and performs to the best of its ability. Throughout this life cycle of performance, the materials as they are layered, encased and standing, expand and contract under stress of our natural environment and to our human environment of desired comfort levels with the help of furnaces and air conditioners.
Dismantlement As the life of the product ages the wood is now either destroyed, recycled, reused, decays or is burned. Further transforming this life cycle yet into another life of other elements including bacterial, biological, and chemical.
A major concern is the impact of the built environment on the planet’s forest resources. Rapid human economic development has relies on the extraction of timber from ecosystems. Natural systems are being replaced with plantations, urban sprawl and farms and are being depleted more quickly than they are replaced. This is not only having a negative impact on many species as well as the integrity of the larger ecosystems of which they are a part but it affects the ability of the land to sustain human activities, absorb incremental increases in pollution as well as react to catastrophic events such as global warming. There are values associated with intact ecosystems that not only have moralistic and aesthetic significance but also practical economic benefit. Ecological economists refer to the estimated value that nature provides to humanity as nature’s services or natural capital. Ecosystems provide:
Important restorative attributes that will be vital in relation to any effective carbon mitigation and pollution reduction strategy
Tropical rainforests in particular provide us rich storehouse of biodiversity that could have a tremendous impact on human health and healing
Resources necessary to continue human existence
A level of species diversity and aesthetic beauty that has important cultural and social values not just to the people who live in these forests but to all of humanity
210 acres of trees at six feet apart and 1200 per acre have the ability to remove the 1.4 million kilowatt hours of pollutants from oil, gas and coal producing power plants. The impact of human activities relates not only to reducing the quantity of forest resources but also that productive forest ecosystems are being replaced with forest plantations. The ability of intact natural systems to absorb carbon is greater than is the case with artificially created human monocultures.
Each industry metal, glass, wood, and concrete says its industry fares well in relation to the with consideration to ecological impacts. Yet LCA’s to develop a full account of embodied energy are complex and they can be manipulated to sway people who do not understand the way information is presented. The fact is conventional construction industry regardless of material is heavily invested in not only the unsustainable use of fossil fuels but the unsustainable use of natural resources. Despite our desire to be more conscious about environmental sustainability and ecology the built in economic and social disincentives can hinder even the best intentions. When looking at the sustainability of current uses of forest resources we need to understand that we are basically exporting biomass from one region to sustain economic activity and development in another. This if continued indefinitely creates imbalances in the global system that cannot be sustained on an ecological level.
There is an understandable inclination to develop bio-based alternatives to plastics and other energy intensive products such as aluminum, concrete and steel, as part of a larger strategy to move away from a fossil fuel economy. Yet we also need to look at the possible impacts of extracting resources from ecosystems as a way to replace hydrocarbon usage for it is the case that one of the greatest ecological challenges facing humanity is the encroachment of ecosystems and the resulting exponential increase in species extinction.
Earth materials such as Adobe and Rammed Earth can help reduce the environmental degradation currerntly associated with the construction industry. Another advantage of earthen materials is that they can be locally produced reversing trends towards increasing the distance between consumer and producer which end up increasing the embodied energy devoted to the transport of these construction materials.
Human survival depends on responsibility and accountability of our building practices:
Create performance standards in operation that are consistent with moving humans towards the vision of ecological and social sustainability
Choose building materials that have the fewest impacts on the environment
Considerations:
1) Suitability of construction material for needs.
2) Ease of construction, can it be constructed by reservation work force?
3) Sustainability, how much energy did it take to make, are their any toxic by products and how did its removal affect the environment?
4) Maintenance: how long do the materials last, and what are the maintenance costs?
The Phoenix metropolitan area is one of the fastest growing cities in the United States. The majority of building construction is residential and is using fast, easy methods for economic gain that we see all over the country. Adobe and rammed earth construction, could easily replace wood frame construction. Building materials such as adobe and rammed earth fare well in comparison to the wood or metal frame construction in terms of their ecological impacts. Rammed earth when using site resources has the fewest environmental impacts and also operates with the least energy consumed on an annual basis. Adobe and rammed earth building are more labor intensive materials having higher labor costs but they require less in costs of materials as compared to wood framing. One important factor that benefits the wood frame sector is that it is highly rationalized as a building process.
Adapted from Adobe and Rammed Earth Buildings this chart reflects the embodied energy in BTU's required for the production and use of various materials. Soil block has a much lower embodied energy than many traditional materials:
Adobe
The use of surrounding soils to construct earthen buildings is dependent on the soil types. For example one must find the proper soil mixture in order to create an adobe brick or to build a rammed earth or poured earth house. Soil suitable for the construction of abobe, rammed and poured earth building is plentiful in the southwest.
Equipment used in mechanical adobe processing are mostly electric generated and produce approximately 5,000 bricks per 6 hour shift.
Energy consumption for abode block is 5,750 kwh per 5,000 bricks for one house constructed.(10)
In the construction phase energy consumed is about 2,500 Btu's per brick x 5,000 bricks per house = 12.5 million Btu’s expended = 116 gallons of gasoline.
Operation of adobe house consumes approximately 11,069 kwh annually. An adobe house would equal 113,335,491 Btu’s expended divided by 22.07 million Btu’s per ton of coal = 5.135 tons of coal per one year of operation.(10)
RAMMED EARTH
Dig out the site
The ‘5/8"minus’ aggregate is a byproduct of the granite mining process consuming 33 gallons of deisel per house constructed.
Construction of the walls consumes 100 gallons of diesel.
Operation of the constructed house would consume 9,639 kwh = 4.47 tons of coal annually.
Cement
Cement production is relatively energy-intensive however it can usually be produced locally. CO2 is released into the atmosphere, both from the fuels burned to make cement and from the chemical reactions in the material itself (see EBN Volume 2, No. 2 -- March/April 1993 and Volume 4, No. 5 -- September/October 1995).
The transportation of this cut timber and lumber was traced by consumption in Arizona versus import and export factors. It was found that most of the lumber used in the state is from the Pacific Northwest mills. To transport to Arizona there are two methods, by rail and by truck. The total traveled miles from Oregon is 1,419 miles by one train comprising 100 cars and 4 engines on average depending on the total weight of cargo.(9)
The construction of the framing for a wood frame house embodies approximately 105,376,199 Btu’s that is equivalent to 970 gallons of gasoline.(1) Today only 74% of an actual timber is usable. For an average 16" diameter by 16’ long log, approximately 199 bf is obtained.
Possibilities
Use Fly ash and bottom ash with cement to make concrete
Wood chips for wall and roof panels;
Straw residue from rice for wall panels;
Fired bricks for outside walls;
Concrete blocks for outside walls;
Earth blocks for outside walls; and
Compressed earth bricks for outside walls and foundations.
The exterior walls of houses will be constructed with compressed earth bricks. These bricks do not require firing, and do not require a factory to produce. This eliminates a large amount of pollution, not only in the firing of the bricks, but also in the transportation required to move bricks and raw materials. Moreover, instead of Portland cement, the soil stabilizer in the bricks will be one of the new cement-like stabilizers that do not require firing in the production process. Compressed earth bricks are easily produced using a hydraulic press. Moreover, their production will be the source of a new micro-enterprise in the village.
Fly ash as a partial replacement for concrete decreases concete costs but also may have some human health side-effects having to do with radiation.
Fired bricks and concrete blocks were eliminated from consideration on environmental grounds. They are produced in brick factories and require baking in coal-fired ovens. Not only does a brick factory require land area, but the oven-firing operation consumes a large amount of energy. Moreover, the dirty coal used to fire the oven produces a large amount of air pollution that affects the area around and surrounding the production facility.
Traditional adobe bricks are made by mixing mud with straw and then pouring the mixture into molds that are dried outdoors in the sun. Adobe bricks are not stabilized (can be eroded by water) and thus must be plastered with mud and maintained regularly.
Compressed earth bricks provide greater strength than earth blocks and do not require wet mixing and drying. Adding a stabilizer to the earth (such as Portland cement or newer types of bonding agents such as CeraCrete that do not require Portland cement) solidifies the compressed bricks and makes them strong and stable in water--similar to fired commercial bricks. Compressed earth bricks do not require firing, and do not require a factory. This eliminates a large amount of pollution, not only by eliminating the need to fire the bricks, but also eliminating transportation required to move bricks and raw materials. In Longju Village, compressed earth bricks can be manufactured on the construction site with a mix of earth from housing sites or from the aquaculture excavation sites with a small percentage of cement (two to ten percent). The cement controls the compressive strength of the bricks. The quality of compressed earth bricks has steadily improved over the years. State-of-the-art machines can now produce high-strength, durable, and attractive bricks with a tongue-and-groove shape that allows for interlocking wall construction without using mortar. The compressed-earth bricks can be immediately configured into a wall where they cure in Place.
Although perfectly suitable for one-story buildings, tongue-and-groove, interlocking wall
construction may not be appropriate for multi-story buildings with higher levels of stress on the
walls. In this case, compressed earth bricks are appropriate, but the structural engineering of
the building changes. Depending on the application in multi-story buildings, post and beams
with compressed earth brick infill can be used. Or, alternatively, compressed earth bricks can
be constructed with holes in the center. Rebars can then be used as structural reinforcements
for the bricks. With some training, brick production and wall construction can be performed by local villagers, creating a new micro-enterprise.
With a crew of five people, three bricks can be produced per minute.
One cubic meter of sub-soil mixed with two to ten percent of cement results in 110
blocks, each 9 kg in mass, with dimensions of 204mm x 102mm x 255mm. Tests show that the compressive strength of blocks with these specifications is 1600 pounds per square inch (psi) (11.0 MPa), assuming 5% added cement content. Sub-soil in the area needs to have the required clay content to meet these specifications (between 5% and 20%).
A compressed-brick machine produces the bricks on a trailer housing a hydraulic press, powered by an eight horsepower gasoline engine. Portability of the hydraulic press allows bricks to be produced at the construction site and also allows it to be used at construction sites. Provides a micro-enterprise business opportunity for villagers.
Smaller machine costs approximately $40,000.
Larger machines producing more bricks are also available, retail
price of $160,000-$200,000 produces up to 800 blocks per hour.
Portland cement is used as the stabilizer for compressed earth bricks. However Portland cement requires firing to manufacture, is expensive, and contributes to air pollution. CeraCrete is a cement alternative that does not require firing.
Outside walls are insulated with 2.5 cm of foam and stucco.
Foundations are constructed using conventional slab on grate.
Inner walls and ceilings of houses are constructed using straw board.
The Enviro Board Corporation Building System is basic mill design that compresses fiber to make durable building panels.
Can be Operated almost 24 hours per day
Requires five semi-skilled workers per shift.
Uses any agricultural waste fiber wheat straw, rice straw, sugar cane
Produces low-cost panels in a variety of lengths and thickness.
The embodied energy of an item is, in simple terms, the total energy that can be attributed to bringing that item to its existing state. It therefore includes the energy consumed in winning raw materials, processing them and manufacturing composite items as well as transporting materials between and within these processes. In addition it includes appropriate proportions of the energy consumed in manufacturing the machinery and vehicles involved in these processes together with the construction and maintenance of the associated buildings and roads.
A full audit of the embodied energy of any item can be very complex and there are diminishing returns with respect to the accuracy of the calculation the further removed the analysis becomes from the item under consideration. As a result the evaluation is often simplified and Fig.1 presents a commonly accepted definition of the embodied energy of a building.
Published embodied energy figures for common building materials vary enormously and there is often little indication of what has been included in the analysis or how they have been obtained. Transportation component is also often omitted or considered using gross simplifications.
raised important issues with respect to the research method and the accuracy of published figures.
highlighted the importance of transportation to the total.
‘Transportation energy embodied in building materials’ which was successfully completed in March 1997. It involved a full analysis of the transportation of materials to a single construction site and the depth analysis of transportation implications of concrete aggregate and ready mixed concrete.
Transportation energy embodied in recycled aggregates due to the collection of demolition materials and re-distribution of recycled aggregates.
Candace Gossen ECO-CULTURE AND SURVIVAL: SUSTAINABILITY VS. HABIT & BEHAVIOR SUSTAINABLE STRUCTURES
Solar7.83 Portland, Oregon cgossen@solar783.com
ECO-CULTURE
Eco comes from the Greek word "Oikos" meaning house, habitat or environment in relation to ecology. Culture relating to human ecology is a social paradigm
There is a need to understand how energy is consumed. Current building practices make extensive use of finite organic resources that cannot be sustained. We need to consider alternative methods of building construction and materials to create a sustainable society Embodied energy is useful towards this ends because it encompasses the direct and indirect processes of extraction, transportation, construction and operation of each structure that is built. Survival depends on responsibility and accountability of our building practices.
Construction accounts for over 11% of the total energy consumed in the United States annually and 50 percent of this is new building construction, with single family homes the top new construction activity.(1) 90% of new single-family dwellings built consist of wood frame construction. Building materials such as adobe and rammed earth fare well in comparison to the more conventional and traditional methods of residential construction in current practice today.
Using local materials in residential construction could substantially change evolutionary patterns of a culture that is currently exploiting its resources. Despite our desire to be more conscious about environmental sustainability and ecology the built in economic and social disincentives can hinder even the best intentions. Responsibility:
create performance standards in operation
choose building materials that have the fewest impacts on the environment.
When looking at the sustainability of current uses of forest resources we need to understand that we are basically exporting biomass from one region to sustain economic activity and development in another. This if continued indefinitely creates imbalances in the global system that cannot be sustained on an ecological level.
In addition the idea of forest as carbon sinks is negated by the process of cutting down timber more quickly than they are replaced.
to be ecologically efficient they would have to be able to absorb and clean an equal amount of air pollution that is produced. A tree quotient that would represent this ecological balance looks like this: Tree quotient =Total amount of trees: total amount of pollution compound absorbed from the atmosphere.
210 acres of trees at six feet on center and 1200 per acre are required to remove the stack emissions released from the production of 1.4 million kilowatt hours (averaged for oil, gas and coal producing power plants).(10)
In 1981 Richard Stein along with the Stein Partnership and the DOE produced "A Handbook of Energy Use for Building Construction." (1) In this handbook conventional habits and behaviors of the construction industry are accounted for. The research identifies the energy required for the manufacturing and delivering of raw materials to the construction job site for over 400 different building materials and products.
Earth materials (e.g. dirt, adobe, and aggregate) are just one alternative to the consumption of trees for wood products used in residential construction. Adobe and Rammed Earth are building prototypes local to Arizona, and are also effective as thermal mass in the hot arid desert. They can help reduce the reliance on wood products and the environmental degradation involved in the processing of the wood material.
Once arrived at the distributor, the lumber is further divided and shipped again by truck to a local retail supplier. At this point the consumer purchases the materials and again ships them to the building site. Upon reaching the site, the material which was once a simple element, a tree, is now an extremely complex building material that has been transported several hundreds if not thousands of miles away from its home. It has been stripped, cut, bonded, shaped, treated and is now being used in the construction phase of the building project to make a shelter. It is during this construction phase that multiple layers of wood products bonded with adhesives and formaldehydes are sealed, painted and encased with more adhesives, solvents and chemicals to complete the shelter.
The constructed shelter stands and performs to the best of its ability. Throughout this life cycle of performance, the materials as they are layered, encased and standing, expand and contract under stress of our natural environment and to our human environment of desired comfort levels with the help of furnaces and air conditioners.
As the life of the product ages the wood is now either destroyed, recycled, reused, decays or is burned. Further transforming this life cycle yet into another life of other elements including bacterial, biological, and chemical.
The construction industry accounts for over 11% of the total energy consumed in the United States annually. This 11% represents approximately 7,500 trillion Btu, which has the equivalent energy value of 1 ¼ billion barrels of oil. Within the construction industry, new building construction accounts for 5.19 percent of national annual energy consumption. The remaining 5.95 percent is distributed among new non-building construction (highways, railroads, dams, bridges, etc). (Stein, 1981)
The energy consumed by new building construction in the United States has two distinct categories. 15 percent of the total energy is used at the construction site, which equates to approximately 548 trillion Btu. The remaining 85 percent, or 2,925 trillion Btu is referred to as embodied energy, the energy required for the production of materials which are incorporated into buildings.
Embodied energy is the direct and indirect expense of energy to create an element for use in some form or another. Unfortunately there is still very little information concerning adobe, rammed earth, strawbale, and other techniques that use soil, aggregate and organic waste by-products.
In the following paragraphs human shelter is the subject of the research and the cultural habits and behavior of construction are observed with a counteractive look at a more ecological and sustainable way of creating shelters.
The Phoenix metropolitan area is one of the fastest growing cities in the United States. The majority of building construction is residential and is using fast, easy methods for economic gain that we see all over the country. This area is also plentiful in local materials for adobe and rammed earth construction, which could support a more sustainable use of natural resources and promote less environmental degradation. This research evaluates the environmental degradations of using local earth materials as a source of wall framing in residential construction rather than using the more common material wood. Each prototype is compared according
Typically construction involves the use of fossil fuels. Yet as we consider the ecological impacts of timber we also need to look at the possible impacts of extracting resources from ecosystems as a way to replace hydrocarbon usage. were
Diesel for on site machinery
coal for electric generated power
transport of workers and materials
The least impact is the labor intensive materials, buildings that can be constructed using quickly using efficient machinery. Adobe and rammed earth building have higher labor costs but require less in costs of materials as compared to wood framing.
6. COMPARATIVE ANALYSIS
Adobe
beginning with the extraction process, one must find the proper soil mixture in order to create an adobe brick. In Arizona, adobe soil is plentiful, especially near the Phoenix area. The equipment used in mechanical adobe processing are mostly electric generated and produce approximately 5,000 bricks per 6 hour shift. Production is random depending on the demand from construction. The operation cited in this study operates at 115,000 kwh monthly, or 5,750 kwh per 5,000 bricks for one house constructed.(10) In the construction phase it is noted that the energy embodied per adobe brick = 2,500 Btu’s at 5,000 bricks per house = 12.5 million Btu’s expended. In relation to fossil fuels, the energy embodied in 5,000 bricks would equal 116 gallons of gasoline. The operation of the adobe house consumes approximately 11,069 kwh annually. Using Navajo Generating Station statistics from a document "An Evaluation of Alternative Control Strategies to Remove Sulfur Dioxide and Carbon Dioxide at Existing Large Coal-Fired Facilities" Report EA 1989, per kwh there is 10,239 Btu’s expended.(2) Therefore an adobe house would equal 113,335,491 Btu’s expended divided by 22.07 million Btu’s per ton of coal = 5.135 tons of coal per one year of operation.(10)
RAMMED EARTH
The process for rammed earth has two options, either to transport in the aggregate needed, or to dig out the site. It is common to use ‘5/8"minus’ aggregate which is a byproduct of the granite mining process. The diesel equipment necessary in this process 33 gallons per house constructed.
Ninety-Six tons of aggregate is
Each object has a cycle called a "Life-cycle". It has a beginning, an ending, and a new beginning. Energy as matter is only transformed, it can never be rid of. The life cycle of an object, such as a piece of lumber for example begins with a tree. In its natural surroundings the tree grows supporting its needs and wastes and until we modify its environment, the tree continually sustains its ecosystem.
When the tree is cut for use, the process begins with the energy required for extraction. For example, the logging operation that cuts this tree is probably several hundred miles at least from the processing plant. The operation of extraction requires a network of logging roads, sawyers to cut the trees, diesel equipment to perform the cutting, skidding, loading and hauling. Semi-trucks now transport the timbers to a mill for further processing. At the mill the tree now cut into logs is put into a log handler, debarker, deck saw, head
concerned with the study of spatial and temporal interrelationships between people and their economic, social and political organizations.
When we place these two words together in the form of Eco-culture we have a resurgence of a character, a new generation that is attempting to integrate the relationship of science concerned with organisms and their environment with a society of people. This renewed awareness stems from a grave desire for change, in an attempt to right the wrongs of conventional habits and behaviors addressing ecology of design to maintain a healthy planet. The characteristics of this eco-culture wherever feasible choose to use renewable energy sources. They believe that ecology and economics have a life-cycle of embodied energy and the costs include the environmental impacts of technology and the externalities as a result thereof. Conventional cultures live in short-term options, they tend to have little regard for global cultures, and destroy local commonalties. Eco-culture respects the traditional knowledge of existence and supports local materials and biodiversity.
Humans are creatures of habit and our behavior is a reflection upon that style of thinking that is currently creating more destruction and waste by-products such as pollution than our earth can regenerate into its life cycle. Eco-culture is perhaps our new paradigm to an immediate needed change.
rig, a twin band resaw, through a filing room, into edgers, trimmers, sorters, stackers, into computerized dry kilns and then eventually sent to a planing mill. Of this one tree only 75% is usable as milled lumber. The other 25% are scraps that are either burned, or processed with additives into sawnwood products, bark or sawdust. The lumber is further treated chemically and processed for shipment across the country. Again the lumber is loaded onto semi-trucks or rail cars for further transportation to a distributor.
to its direct impact on the environment through measurable energy consumed, including air emissions, and projected land impacts from the use of fossil fuel energy. Results of this research show that building performance of a construction prototype is not the only consideration in choosing a construction material. It also shows that the entire energy path must be considered in order to make the proper choice for sustainability.
The four step "process" focuses on:
1) Extraction - of the simple element such as a tree and soil and all of the equipment necessary to do so.
2) Transportation - including all vehicles, rail and truck and their consumption of fossil fuels.
3) Step three identifies the energy embodied in the building materials and the construction sector. The study analyzes the actual Btu’s expended per wall construction material created. For a relative comparison to energy, it is further translated into Btu’s per gallon of gasoline.
Energy used to operate the house on an annual basis, given in kilowatt-hours.
Air emissions including CO, Nox, HC, Pm, Co2 and So2 are emissions from the machinery necessary to process each building prototype, whether it be from stationery diesel, mobile diesel, electric generated equipment or electric generated power. These figures were taken from various sources. (2,3,4,5)
Land, water, trees and fossil fuel impacts are all included in Table 4 which are relative to coal operated power plants.(7) In the paper titled "Land requirements for the Solar and Coal Options," it is noted that the total land disturbed due to the operation of Navajo Generating Station is 6.62 ac per NW. (7) This includes all land affected for the generating station site, ash disposal area, evaporation ponds, well field and pipeline, station access roads, railroad, transmission lines, mines and limestone source. Navajo Generating Station was chosen for this study due to the consistent operation of this plant, information available and more closely related to electric power supply to Phoenix through this generating station.
WOOD FRAME
There is quite an extensive network involved in the timber industry and that is why this study was quite specific in documenting only milled lumber used in the framing of a house. For an average 1,500 sf house there is 14,307.6 bf used in the walls and roof. In comparison both the adobe and rammed earth prototypes used 1,900 bf for the roof framing only.
Total skidding, loading, and hauling for production of one house consumes 119.52 gallons of diesel per 14,307.6 bf of lumber, or 20 trees. Then milling consumes 3.3 bf/kwh.(9)
Multiplying for 14,307.6 bf for requirements of one house that would equal to 47,215.08 x 10,239 Btu’s = 21.9 tons of coal for electric generated power.
Transporting this cut timber and lumber from the Pacific Northwest mills to Arizona involves two methods, by rail and by truck.
Construction of the framing for a wood frame house embodies approximately 105,376,199 Btu’s that is equivalent to 970 gallons of gasoline.(1) but only 74% of the actual timber is usable.
"a climate crafted home" built to save 25% of the energy consumption of competitive homes.
Wood frame house consume uses 5.67 tons of coal yearly.
rammed earth prototype uses 4.47 tons of coal annually.
Rammed Earth option #1 (to excavate the site out) had the fewest environmental impacts. A rammed earth house operates with the least energy consumed on an annual basis for the Phoenix area.
The largest consumption of energy is from electric generated machinery and the greatest amount of air emissions is from electric generated power.
The fewest amounts of trees required were equal for adobe, and rammed earth, with a ratio of 7:1 for a wood framed house to an adobe and rammed earth house
9. REFERENCES
Stein, R.G., 1981. Handbook of Energy Use for Building Construction, USDOE/CE1220220-1. March 1981.
Environmental Protection Agency, 1989. An Evaluation of Alternative Control Strategies to Remove Sulfur Dioxide and Carbon Dioxide at Existing Large Coal-fired Facilities. NEDS Point Source Listing 1985. Report 1989-January 3, 1989.
Arizona Department of Environmental Quality, 1992. Emission Factors for Gasoline and Diesel Powered Industrial Equipment. Emission Factor Ratings, Table 3.3-1.
Arizona Department of Environmental Quality, 1990. Air Quality Control for Arizona. Office of Air Quality. Annual Report, August 1991.
Arizona Corporation Commission. Interview with David Berry, by author. Written interview, October 1992.
Environmental Inspection Agency, 1992. Cost & Quality of Fuels for Electric Utility Plants 1988, Arizona Public Service, Co. Phoenix. 1988
Table 50 gas units. FERC Form 1.
Pasqualetti, M. and Miller, Byron A., 1984. Land Requirements for the Solar and Coal Options. The Geographical Journal, volume 150, number 2, July 1984.
Arizona Public Service & Arizona Electric Power Cooperative operated units: data from LCP filing in April 1989.
Georgia-Pacific. Clemet Falls, Oregon 1992. Interview with Peter Hess, Norm Edwardson, by author. Telephone interview January 1992.
Gossen, C. 1993. Adobe, Rammed Earth and Wood: An Energy-Based Environmental Analysis of Residential Construction in Phoenix, Arizona. Arizona State University Library. May 1993.
Materials Report
Here is some preliminary research that I have come up for the basic materials that will be used in the construction of this building. In selecting the materials for the construction of this project, there are several things that need to be considered.
1) Suitability of construction material for needs.
2) Ease of construction, can it be constructed by reservation work force?
3) Sustainability, how much energy did it take to make, are their any toxic by products and how did its removal affect the environment?
4) Maintenance: how long do the materials last, and what are the maintenance costs?
Cement
One of the major advantages of concrete is that it is one of longest lasting building materials. This means that over the long term it may be the most ecologically sensitive materials. However the problem we face is one where the ecological challenges remain present in the short term.
Cement production is relatively energy-intensive. Large amounts of CO2 are released into the atmosphere, both from the fuels burned to make cement and from the chemical reactions in the material itself (see EBN Volume 2, No. 2 -- March/April 1993 and Volume 4, No. 5 -- September/October 1995). Millions of cubic feet of concrete is now used to rapidly expand the built environment to address human needs in relation to dramatically increased levels of population and consumption. Total world cement production has increased more than four fold since 1960 (Living Planet Report WWF 1998 Page 9).
According to the Holman company (a major concrete producer) the impact of concrete on greenhouse gas emissions can be significantly reduced by rewriting building codes to allow and promote the use of flyash in concrete. Ten of the world's largest cement producers are collaborating on a two-year, $4 million study of how the cement industry can become more sustainable. Battelle Memorial Institute in Columbus, Ohio, is conducting the research, under the auspices of the World Business Council for Sustainable Development, based in Switzerland. The study will provide the cement industry a major user of energy and natural resources with a roadmap to move it closer to long-term sustainability (CEMENT INDUSTRY STUDYING SUSTAINABILITY Green@Work, Sep-Oct 01, p 12).
Composite Concete blocks
One solution might involvesthe use of ICFs (Insulated concrete forms) and ICBs (insulated concrete blocks).
Concrete blocks (ICBs) such as integra and Rastra are made up of composite materials such as cement and polystyrene to create materials that have both insulative capacity and thermal mass. Tom Hahn says they offer significant fire protection, are bug proof and use less concrete per square foot of wall than ordinary concrete walls. Rastra is glued together with an expanding foam. ICFs Filled with foam can have an insulative value of R 6.5 per inch. At the APS Solar Home these blocks were simply sandblasted on the outside and a sealer was then applied. Tension rods within the walls actually eliminated the need for grout cells, similar to straw bale building techniques.
WOOD FRAME
There is quite an extensive network involved in the timber industry and that is why this study was quite specific in documenting only milled lumber used in the framing of a house. For an average 1,500 sf house there is 14,307.6 bf used in the walls, floor and roof. In comparison both the adobe and rammed earth prototypes used 1,900 bf for the roof framing only.
There are generally 12-16 sawyers daily that work for one particular cut or sale area. As an average there is among 6-25,000 bf cut daily over 160 acres in 7days.(8) Diesel is used as an energy source and the statistic base is the same as used for adobe and rammed earth. Total skidding, loading, and hauling for production of one house consumes 119.52 gallons of diesel per 14,307.6 bf of lumber, or 20 trees.
Once the timbers are cut then they must be milled. The procedure for milling follows in diagram and consumes 3.3 bf/kwh of production.(9) Multiplying for 14,307.6 bf for requirements of one house that would equal to 47,215.08 x 10,239 Btu’s = 21.9 tons of coal for electric generated power.
The transportation of this cut timber and lumber was traced by consumption in Arizona versus import and export factors. It was found that most of the lumber used in the state is from the Pacific Northwest mills. To transport to Arizona there are two methods, by rail and by truck. The total traveled miles from Oregon is 1,419 miles by one train comprising 100 cars and 4 engines on average depending on the total weight of cargo.(9)
The construction of the framing for a wood frame house embodies approximately 105,376,199 Btu’s that is equivalent to 970 gallons of gasoline.(1) Today only 74% of an actual timber is usable. For an average 16" diameter by 16’ long log, approximately 199 bf is obtained.
Adobe Block
Clay Mine Adobes require no sealing or other expensive upkeep and adapt readily to modern energy-efficient and solar designs
Composite Blocks
Rob Tucker from Castleblock says that his company's products make use of recycled material bases. Cempo form, is a composite material made up of cement and polystyrene. Cement content is 14 percent while the polystyrene makes up the rest. Recycled content is 86% by volume. R-value of 10" block is 36.44. Lifespan of these structures (as per U.S. Navy engineering) is 200+ years. Termite, wind, earthquake and fire resistant." He adds that the Manufacturing of Cempo involves no heat processes and the total electrical service for the factory is 500 amps.....very low-key energy wise. Motor is required to bond the bricks together, and concrete to fill in the hollow interior. rebar is required to reinforced the structure much with traditional block. Factory is close by in Pahrump, NV. Tucker seems quite enthusiastic about the opportunity "to work with the Hopi Tribe on housing issues." And he also said that "Cempo is a system which is very user friendly and can be built with local labor quickly and efficiently."
Rastra is a material that is similar to Cempo, except that it is bonded together with a special adhesive. The Rastra system--a European technology that is now getting established in the western United States. The Rastra system uses 100% recycled expanded polystyrene (EPS) foam, ground into small beads and mixed with Portland cement. Functionally, Rastra has a big advantage over most other foam form systems in that the cement prevents insect infestations. Although insects don't eat polystyrene, they often nest in it and can be hard to remove. The sealant that Rastra recommends to join its blocks together is a expanding foam that seals the blocks together and holds them in place until the concrete is poured Touch N Seal from Sealant Products, Inc. of Santa Ana, California. The problem with this is that while the smaller cans use the larger canisters use a hydro-chlorofluorocarbon (HCFC) propellant.
The embodied energy is the amount of energy required to make the product. Transport from the point of extraction as raw material to the factory and then the distribution and end use also has an ecological impact of using a material.
Steel or aluminum have very high embodied energies
Concrete and other masonry products have a moderate embodied energy.
Earthen materials have a low embodied energy because they are local, plentiful and do not require refining or processing.
By recycling and reusing materials we can reduce the embodied energy of building materials. Reuse durable materials such as doors, windows, fixtures and lumber.
The ReUse Center in Ann Arbor accepts and resells used and surplus building materials so that they are not wasted. Similar operations exist throughout the nation.
Manufacture and use building materials from recycled materials.
Manufacturing new steel or aluminum from recycled sources dramatically decreases the energy used.
Concrete, wood, gypsum, and metal building materials can be recycled into new building products.
Building materials can be made from totally different consumer products such as carpets made from recycled plastic bottles, insulation from recycled newspapers, and outdoor decking from plastic grocery bags
Considerations of environmental impact relate not only to energy use but also consider ecological impact of producing building materials. Polyvinyl chloride PVC is made from chemicals that create pollution during various stages of their life-cycle, from extraction to manufacturing to disposal. Copper is more expensive but it has a much lower ecological impact although copper mines and the smelting of copper has ecological impacts as well.