What is termed "green" construction today has in fact existed since the time when man made his first shelter. Indigenous material and labor were used, minimal damage, if any, was made to the natural environment, and the fate of future generations was in no way affected by the construction.

These design and construction methods ended during the industrial revolution with the development of effective mass production techniques and the increase in transportation opportunities to send products around the country and world. No longer did builders rely on local materials and products, they used cheaper mass produced items that had been developed in other regions, with different resources and climates. The idea of mass production carried over into the housing market as neighborhoods began being assembled in no time, particularly after World War II (Housing (shelter), 2001). Also, with the development and incorporation of mechanical, electrical and plumbing devices into homes came a desertion of regional techniques used to heat and cool homes, illuminate homes and to provide and remove water and waste from houses. Finally on a broader level, came the destruction of land caused by mining and drilling needed to create new housing products.

These housing methods continued until the 1970’s when two events triggered a turn in attitudes about construction techniques. The first was the original Earth Day in 1970 in Rio de Janeiro, and the second was the oil embargo of 1973. The first Earth Day made people aware of the limits of natural resources (Bynum and Rubino, 1999) as the earth’s population boomed (Robinson, 2001). The oil embargo alerted consumers of their dependence on oil and oil products. It also created a desire to create materials and systems that required less oil or energy and therefore less cost. This was the beginning of an awareness and desire for energy efficiency. (Baker, Elliot and Banta, 1998)

Since the energy crisis, the energy efficiency of homes has increased 35% (Green Building: A Primer, 2000). However, home construction and the resulting land destruction has continued at an enormous pace. Home size has consistently increased so that while the average home in 1970 was 1,400 square feet, today it is 2,200. (Learning Network, 2001) The number of homes has increased as well, from just over 80 million in 1980 to over 112 million in 1998 (Household and Housing Unit Estimates, 1999). Also, the use of inexpensive synthetic building products has proliferated with the toxicity of very few of these products ever being tested. This is very dangerous with the increasing air-tightness of homes to conserve energy. In fact, the EPA has stated that indoor air pollution is one of the "most serious potential environmental risks to human health." (Baker, Elliot and Banta, 1998)

With this continuance and increase in environmentally destructive and harmful processes, many groups have seen a need to stop this chain through outreach methods and education resulting in a return to a more sustainable method of living. One of the first groups in the residential sector to formalize an improvement plan started in the early 90’s in Austin, Texas. Here, energy enthusiasts started the Austin Green Building Program (Green Building Program, 2001). Today, the Program includes a checklist of 170 items with four rating levels based on the number of items incorporated into the design, construction and marketing of the home. Participating builders in turn receive positive advertising, training in new techniques and a sense of pride in their city’s future (Local Green Builder Programs Profile, 2001).

Since the beginning of Austin’s residential program, more than ten programs have started around the country, with many more in the planning phases. The popularity of these programs is increasing the chances of a nationwide change in the residential market. Studies have indicated that residents of environmental communities are happier, healthier and more productive (Green Building: A Primer, 2000). However, no studies regarding the environmental effects of these programs on their communities were found, thus reinforcing the need for research in this area. Regardless of the exact effects, they most certainly vary between locations. This is due to significant differences among the present programs because currently there is no standard that defines green-built housing (Defining what "green" means, 1999).

Not only is an effort being made among housing program groups, but universities are also working to educate students in the hope that they will employ green techniques after graduation. Traditionally, any emphasis on green education has been aimed primarily at architectural students. There are a host of programs throughout the country termed "environmental design programs". However, most are really architectural or planning programs with an emphasis in green design. Very few construction programs focus on green residential design. Upon reviewing all 92 Associated Schools of Construction member universities in the United States through the ASC web page, only eight were found that even mention environmental considerations in any of their course descriptions. These included Virginia Polytechnic Institute and State University, the University of Louisiana at Monroe, Minnesota State University Moorhead, Alfred State College, Old Dominion University, Texas A&M University, Georgia Institute of Technology, and the University of Florida. Of these, only a few deal exclusively with environmental issues such as the University of Louisiana at Monroe’s "Environmental Construction" course, Georgia Institute of Technology’s "Lab for Sustainable Design and Construction", and the University of Florida’s "International Sustainable Development" and "Natural Hazards" courses. The reasons for the lack of green education in most construction programs are not known. Possibly it is because some feel constructors have little control over what actually goes into a structure; they simply build what designers specify. However, numbers of construction students graduate to become homebuilders who both design and build. Maybe it is because environmental considerations are often more expensive upfront than the alternative which could lead to an inability to compete cost-effectively. Today, though, more educated owners are demanding green buildings and appreciate builders that present information on environmental alternatives. Or finally, it could be because no concrete definition or guidelines have been created to allow educators to know exactly what would be taught in a green residential program and therefore courses or a focus have been shied away from.

The exact definition of green construction varies among sources and people. Many define green as synonymous with sustainable (Talarico, 1998). Another definition, from Steve Loken, keynote speaker at the 1999 Green Building Conference in Denver, is that green building is the "appropriate use of technology and resources" (Defining what "green" means, 1999). Architect Anthony Bernheim defines green building as "designing for higher levels of energy and resource efficiency, indoor air quality, and environmental performance well beyond code requirements." (Bernheim, 2001).

Without a doubt, green construction is not merely a component-by-component substitution for traditional building products. Instead, it is a "whole-building" approach to design (Bynum and Rubino, 1999) taking into effect not only construction techniques, but also reduced energy consumption, protection of ecosystems and occupant health (What is green building?, 2001). One reason a lack of consensus exists over a formal definition is because all environments are not the same, and each homebuilder has different considerations for what will best suit their location and buyers needs (Defining what "green" means, 1999). Even so, major classifications of green characteristics can still be the same for each area with a few varying specifics within. The challenge then is deciding what the major classifications should be for a green residential program. If this were done, new and developing programs would not have to reinvent the wheel when deciding on builder checklists. A national guideline would also aid educators by presenting the major green aspects that have been deemed important. It will also serve as a guideline for teaching much as the Construction Specifications Institute’s (CSI) masterformat does currently for courses such as materials and methods and estimating. Finally, consumers would also benefit from the knowledge of all the various aspects available to create green or greener homes (Establishing Priorities with Green Building, 1995).

The closest guide that currently exists for a national green definition and guidelines was created by the United States Green Building Council’s Leadership in Energy and Environmental Design (LEED) program with a focus primarily on commercial construction. One of its major goals was to define "green" and provide a standard for measuring building compliance. (An Introduction to the U.S. Green Building Council

, 2001) From the efforts of industry and environmental leaders within the organization, green has been defined as "Design and construction practices that significantly reduce or eliminate the negative impact of buildings on the environment and occupants in five broad areas" (An Introduction to the U.S. Green Building Council

, 2001). LEED’s five areas include site, water, energy, material and resource conservation and indoor environmental quality. From the work of LEED and existing residential green builder programs, a formal categorical system for residential environmental issues could be developed that would allow for more organized implementation of green builder programs and a refined guideline for the teaching of green issues as related to residential construction.

This study focuses on eight major green building programs from around the country that include rating systems for homes. Each of these programs is unique in its method of rating homes, number and type of items included in the checklist, minimum requirements, number of rating levels and point values for each item. By analyzing and comparing these programs, the most important aspects of green residential construction should come to light which will in turn lead to a clearer understanding of important green concepts. From this, a formal classification system could be developed for use both in green programs and green education. Table 1, Characteristics of Eight Regional/City Green Builder Programs, below addresses maximum and minimum point requirements for the eight programs and whether compliance is determined by the builders themselves or if an inspection is needed. Half of the eight programs require compliance with all items in a "Section 1" group and additional points from other major categories. The "Section 1" ranges from two to six items and includes things such as compliance with state energy and ventilation codes, Energy Star certification, and compliance with water use efficiency standards.

To determine if a consensus could be reached concerning green home characteristics, general categories were first compared among programs for similarities. Categories can be defined as broad groupings of items related by their benefit to a certain area of the environment, such as land, air or water or by their advantage over traditional construction methods such as material or energy efficiency. Several of the programs had categories broken down into specific areas such as "Energy Use: Insulation and Air Sealing", "Energy Use: Glazing", "Energy Use: Glazing" and so on. For the purpose of comparison in this study, these smaller categories were simply combined into "Energy Use". Additionally, not all programs had the exact same title for each category. For instance, the category of site/land use had many related titles between programs such as "Landscape Conservation", "Site Planning", "Land Use", "Treat Site Appropriately", "Site Use", "Site", and "Site and Water". Table 2, entitled Number of Study Green Builder Programs With Similar Green Characteristic Categories Included In Rating Checklists, provides results from the category comparison.

The six major categories of site/land use, air quality/health, energy efficiency, materials efficiency, water, and waste management are included in the checklists of over half of the programs studied. These correspond to the categories used in LEED’s Green Building Rating System with the addition of waste management.

Next, individual items were compared within categories for the six major classes above. Checklist items include specific features or measures taken to lessen the environmental impacts of a residence. These items are assigned a point value. For some programs the point system is weighted to reflect the degree of effort or cost associated with each. Other programs do not differentiate and simply assign a point value of one to each checklist item.

To compare the items within each category such as site/land use, each specific item included under the heading of site/land use was first compared among programs. Once these items were compared, the same items classified under different category headings were included. As in the category comparison, titles for items were not exactly the same between programs. For example, for the item below of "Rainwater recovery and infiltration from roof", titles from programs included: "Rainwater harvest system", "Provide infiltration system for roof runoff", "Rainwater harvesting for landscaping" and others. Table 3, Comparison of Green Checklist Items Within the Site/Land Use Category Among Eight Study Green Builder Programs, illustrates a checklist item comparison for the Site/Land Use category. From this analysis it could be determined how often each specific item was included within the eight programs and also if it was included in the same category for the programs a majority of the time.

Table 3 illustrates how many items of the 49 items included in any program’s site category are included in each program and under what category they are classified. Often, a checklist item included in one program’s Site/Land Use category is included in other programs under a different category. For example, while rainwater recovery and infiltration was included in all eight programs’ checklists, it was included only half of the time under the category heading of "Site/Land Use". In the other four programs it was grouped under "Water".

After comparing green checklist categories between programs a group of six categories emerged that were present over 50% of the time in the eight programs included in the study. These included:

Therefore, it can be concluded that these are important characteristics of a green home and should serve as major groupings if a classification system for green products and services were developed. These should also serve as emphasis areas for residential green building courses.

The specific contents of each of these major categories were then analyzed to determine if they were consistent between programs. Upon analysis it is evident that major differences do exist. For instance, in the site/land use category there were four items that were included in all eight programs, definitely indicating a significant green measure, but of these only one item was included in site/land use even half of the time (rainwater recovery) while the other three were included in only one or two of the programs under the heading of site/land use. This same condition was observed repeatedly when the other five categories were compared in detail.

The lack of consistency between programs illustrates the difficulty in categorizing items in a specific group because they often relate to multiple categories. For example, when determining what the nature of rainwater recovery is in regard to green residential construction one could say it pertains to water conservation, others the reduction of erosion due to run-off and still others a reduction in utility burden. The various benefits make rainwater recovery pertinent to four possible categories: water, site/land use, waste management and materials efficiency. This example is not uncommon and thus reinforces the need for a predetermined classification system, similar to the CSI divisions, so the debate of where to include each item is already solved and a master list of green items exists for ease in starting new green builder programs and for educational purposes as well. The specific items within each of the six classification groups could be determined through several methods. First would be a majority consensus among green building programs. For example, if an item is included in six programs’ lists and in the same category four of the times, it would be categorized according to the four majority. Another option would be a synthesis of the LEED categories and items with determinations made by a panel on those items not included in LEED’s program that would be applicable to the residential sector. A final option would be the development of an industry expert panel that would carefully analyze each item and come to a consensus on which category it would be most appropriate in. With a formal categorical system, green courses could be taught in units using the six classification systems named previously with specific items as determined covered in each. This would ensure that all aspects of green construction were being covered among those schools choosing to incorporate green courses, much like the CSI divisions are used to ensure similarity of information for material and methods courses today.

An up-to-date categorical system with all green options or techniques available would also aid educators in the awareness of the latest in green construction. They could then use this information and incorporate it into existing courses such as materials and methods, mechanical and electrical systems, field operations, project administration and others if they did not have the ability or desire to create classes focused entirely on green construction (Mead, 2001). The green master format list would serve as a guide for educators that are unfamiliar with green advances to easily locate those items related to their respective area and then learn more. By incorporating green techniques and product information into several courses, green principles would be enforced throughout a student’s education, perhaps leading to a more lasting impression (Mead, 2001).

As new green products and systems are developed, a board would have to be created to place these items within the green classification system. Also, the stance of the National Green Building Conference that builders should adopt the definition that best suits their location (Defining what "green" means, 1999) would still apply as builders would choose those items that apply only to their region as builders do now using the CSI system. A green classification system could only facilitate more green construction and green education as well as alleviate the time and headaches of deciding the appropriate categories for green items.

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