By Deborah Jackman, PhD, PE, LEED AP™ - originally posted on 01/11/2013

trummerfrauen.jpg

The Painting and its Historical Significance:
“Trümmerfrauen” means “rubble women.” The painting, created in 1951 by Johvi Schulze-Görlitz, depicts a group of women sifting through the rubble of a bombed-out building, reclaiming bricks. The woman in the foreground of the painting is chiseling mortar from the bricks, so that they can be reused in subsequent rebuilding projects. The need for this reclamation speaks to the utter devastation inflicted by the Allies upon Nazi Germany at the end of World War II. That women, rather than men, were engaged in this back-breaking labor speaks to the fact that a large percentage of healthy, working-age German men were killed or captured during the war and were not available to help rebuild. Even the date of the painting is telling. While the war ended in 1945, even as late as 1951 significant areas of German cities still lay in ruin. Rebuilding continued well into the late 1970s in some areas. After the War, there was an estimated 14 billion cubic feet of rubble from destroyed buildings scattered throughout what was then West Germany [1]. All major German cities were affected. An estimated 80% of all historic buildings located in cities were destroyed. Housing was scarce because 6.5 million apartment units (out of a total of 16 million units) throughout West Germany had been destroyed in the bombing. While some of the rubble was reclaimed and reused in new construction projects, much of it was just piled up to create man-made hills. The rubble had to be consolidated so that still intact buried infrastructure such as sewer and water lines could be accessed during rebuilding. The Teufelberg (Devil’s Mountain), a mountain constructed of rubble located in Berlin, is 115 meters tall and is the second highest point in the city. There are even recreational sites located in modern Berlin, Leipzig, Frankfurt, and other cities used for snowboarding, paragliding, and rock climbing that have been created from these artificial urban rubble mountains.

Eventually, through hard work and resources supplied to it by the U.S. as part of the Marshall Plan, Germany did rebuild itself. Today, it has the largest economy in Europe, with a strong manufacturing base, a highly trained workforce, and low unemployment. Along the way–and likely due in part to its rebuilding experiences after the War– Germany has also become an international leader in the modern green building movement. Today, the average building in the U.S. uses approximately one third more energy than its German counterpart [3].

This essay will provide an overview of the modern green building movement, a summary of the various green building rating systems in use, and will look at the role that material selection and reuse plays in that movement.

The Green Building Movement—Definition and History:
At its most fundamental, a green building is one that minimizes negative impacts on the environment both during its construction and operation. Negative environmental impacts are those that contribute to the depletion of the Earth’s non-renewable resources or which degrade ecosystems. To understand how much impact buildings have on the environment, one need only consider that 40% of all energy used in the United States today is used to operate buildings. This amount of energy equals the amount of energy used for all transportation functions (automobiles, trucks, trains, planes, and buses) nationwide. Most of this energy comes from non-renewable sources and results in the generation of significant amounts of greenhouse gases. And, energy use is only one factor among several building-related factors that impact the environment. A number of rating systems and design protocols have been developed to assist architects and engineers in making sustainable choices as they design a building. Some of these “green” practices have also made their way into revisions to various building codes—a necessary step for institutionalizing green building strategies within the mainstream building design and construction industries. Before discussing specific green building strategies and rating systems, it is helpful to understand how these strategies and systems came to be. It is informative to look briefly at the history of the green building movement.

Most scholars of the green building movement mark the start of widespread interest in sustainable design with the publication of Rachel Carson’s Silent Spring in 1962. This seminal work spurred development not only of the green building movement, but of environmentalism in general. It directly led to the U.S. ban on DDT, and was a catalyst for much of the major federal environmental legislation of the 1970s, such as the Clean Water Act, the Clean Air Act, and Superfund legislation. Internationally, this heightened interest in the environment led to the 1972 Earth Summit, held in Stockholm, Sweden, and attended by representatives from 113 countries. As an outgrowth of this first Earth Summit, the Declaration of the UN Conference on Human Development was developed—a document that outlined 26 principles related to sustainability and human activity. Participants of this first Earth Summit also agreed to reconvene every 10 years to reassess progress toward achieving environmental goals [2].

Nearly concurrent with the first Earth Summit was the first Arab oil embargo of the U.S., also occurring in 1972. The Oil Producing and Exporting Countries (OPEC), a confederation of oil-rich nations, mostly in the Middle East, ceased oil exports to the U.S. for political reasons. This created a temporary petroleum shortage in the U.S., driving gasoline prices to record highs and creating national interest in alternative energy sources and in energy conservation. With the creation in 1977 of the Department of Energy (DOE) and the National Renewable Energy Laboratory, the federal government increased funding of research into various renewable energy technologies such as photovoltaic (solar) energy and wind energy– technologies that at the time were in their infancy, but which today have advanced to the point of being widely accepted alternatives to fossil fuel-generated electricity. The emphasis on energy conservation produced legislation to increase the fuel economy of automobiles. It also caused changes in building codes to ensure more energy efficient building envelopes. Once U.S. oil supplies appeared to regain a more secure footing starting in the early 1980’s, energy prices dropped and many U.S. consumers and businesses largely ignored energy conservation and alternative energy issues for the next two decades. Yet, many of the structural changes created during the oil embargo years—work of the DOE to fund energy research within universities, automotive fuel efficiency standards, and building code changes to foster building envelope efficiency—remained, and work continued in the background, largely out of public view.

A third key event in the evolution of the environmental and green building movements was the formation in 1987 of the Brundtland Commission. The Brundtland Commission was convened under the authorization of the United Nations General Assembly to create a white paper on what constituted sustainable development. The resulting report, “Our Common Future,” had as its principle premise that sustainable international development was the process by which we “meet the needs of the present without compromising the ability of future generations to meet their own needs” [2]. The Brundtland Commission’s work is perhaps most significant because it promoted action on the part of European and Asian nations to create and enforce standards to foster environmental responsibility. As impactful as the Arab oil embargo was to U.S. attitudes about energy conservation, the Brundtland Commission was probably a greater influence outside of the U.S. Hence, as popular interest in energy conservation waned in the U.S. during the 1980’s, it increased in Europe. Subject to higher energy prices than in the U.S., European businesses and consumers in the 1980’s and 1990’s had a much larger financial incentive to conserve energy and to explore alternative energy technologies.

The work of the Brundtland Commission spurred a movement among European architects to incorporate sustainable features into their buildings. By the early 1990’s, many European governments had mandated requirements for minimum energy efficiency standards in buildings. Building designs featuring sustainable elements became prominent in the work of such well-known European architects as Norman Foster and Willem Jan Neutelings [3]. U.S. architects recognized this emerging European design trend and realized the need for the development of sustainable building standards in the U.S. A principle difference, however, between Europe and the U.S. is the degree to which the respective governments practice centralized planning, and regulate building and development. The degree of regulation is much higher in Europe. So, whereas energy efficiency standards for buildings were mandated by many European governments by the 1990’s, architects and engineers seeking to develop consistent standards for green building in the U.S. had to largely rely on the development of voluntary, industry-based standards. In 1993, the United States Green Building Council (USGBC) was formed as an outgrowth of discussions conducted during the American Institute of Architect’s (AIA) World Congress of Architects meeting in Chicago of that year [2].

The USGBC unveiled the first version of its Leadership in Energy and Environmental Design (LEED) green building rating system in 1998, after several years of discussions among its membership. The development of the first version of LEED was stimulated by a memo of understanding between AIA and the DOE, finalized in 1996 during the Clinton administration. The memo of understanding called for the establishment of a roadmap for sustainable buildings for the 21st century and promised government support in the form of grants for research related to this goal. An executive order made by President Clinton in 1998 mandated all government buildings to improve their energy management and to incorporate “environmentally preferred” material choices whenever possible [2]. While not directly impacting private buildings, this executive order provided impetus to the development of much of the intellectual infrastructure needed for a more integrated approach to sustainable design within the U.S. in subsequent years. LEED was revised and updated to Version 2.0 in 2000 and again, to Version 2.1 in 2002, Version 2.2 in 2005, and Version 3.0 in 2009, all in response to an increased interest in green building and to efforts to apply consistent metrics to what it means for a building to be “green.” In the early 2000’s, after 9/11 and the ensuing Iraq war, energy prices again rose and public interest in renewable energy and energy conservation re-emerged. Around this same time, a number of prominent extreme weather events occurred world-wide (droughts, hurricanes, floods), which many attributed to global climate change caused by greenhouse gases. The cumulative effect of all of these factors is that today interest in green building is high. Green buildings are no longer viewed as exotic, but as mainstream. Because more architects and designers are now familiar with the strategies and tenets of green design, design premiums that were previously assigned to certified green buildings have greatly diminished. Owners and architects alike understand that on a life cycle cost basis (which considers both construction and on-going operating costs), a well-designed green building is actually less expensive than one that is designed using older conventional standards.

Green Building Rating Systems:
Especially in the early days of the green building movement designers were not always clear on what constituted a “green” or sustainable building design practice. A strategy or material that initially seemed like it might be the greenest choice turned out, after further analysis, to be less green than other alternatives. The need to establish objective standards for what building design practices were sustainable was the driver behind the establishment of various building rating systems. Given below is a brief summary of the major green building rating systems in use today and their primary criteria.

  • BREEAM (established in 1988 by the British Building Research Organization)
    Even though LEED is the best known rating system in the United States, it is not the oldest. BREEAM was established by the British in 1988 and is the oldest green building rating system in wide spread use. It was directly inspired by the same wave of environmental activism in Europe that surrounded the formation of the Brundtland Commission discussed above. It is used widely in Great Britain, Germany, France, Spain, and Italy. It assesses buildings in the following areas:

     

    Credits are awarded in each category, the credits weighted relative to the importance of each category, and a building receives one of four ratings: Pass, Good, Very Good, or Excellent. A certificate is awarded that can be used for promotion by the building owners. BREEAM covers residences, offices, and industrial facilities, with different assessment methods for each category.

    1. building management (during construction, commissioning, and operation);
    2. energy use;
    3. health and well-being of workers and occupants;
    4. water and air pollution generated by the construction and on-going operations of the building;
    5. transport (CO2 generated to travel to and from the building);
    6. land use (greenfield and brownfield sites);
    7. ecology (protection of sensitive building sites);
    8. material (low impact materials based on life cycle analysis); and
    9. water (consumption and efficiency).
  • LEED (Leadership in Energy and Environmental Design, established in the U.S. by the USGBC in 1998 with updated versions since)
    This is the major rating system used in the U.S. It consists of seven categories of evaluation criteria:

     

    Each category has a maximum number of points assigned to it and if a building design and construction process meets a given criteria, it earns points for that category, up to the maximum limit. Total points are then calculated and a building earns a Certified, Silver, Gold, or Platinum rating. Like BREEAM, a certificate is issued that the owner can use for publicity purposes. LEED ratings systems for new commercial construction, core and shell construction, and schools are available. While the topics are organized and subdivided somewhat differently, the fundamental parameters which determine building sustainability are very similar between BREEAM and LEED. One significant difference between the two is in how they were developed. BREEAM was created by a British national standards agency and then was adopted by various developers. LEED, on the other hand, was developed by consensus within the private sector by conversations and debate between architects, engineers, and other interested parties. Other important points related to LEED include the fact that the regional priority credit category is new with LEED Version 3.0 and was added to address the criticism that there needed to be flexibility built into LEED to allow for regional differences. Also, in going from LEED Version 2.2 to Version 3.0, categories were reweighted to give greater importance to energy conservation and water conservation—arguably, the factors having the greatest environmental impacts.

    1. sustainable sites;
    2. water efficiency;
    3. energy and atmosphere;
    4. materials and resources;
    5. indoor environmental quality;
    6. innovation and design process; and
    7. regional priorities.
  • Green Globes (originated in Canada but becoming popular in the U.S)
    Green Globes is questionnaire-driven, with questions asked of the designer and builder related to seven categories:

     

    Again, except for the organization of the categories being slightly different, the essence of what constitutes valid criteria for a sustainable building project is similar to LEED and BREEAM. One major difference is that in addition to designers answering the questionnaire, the building project is only certified once a third party auditor does a site inspection/audit to verify that the features reported were in fact implemented in the building. Neither LEED nor BREEAM actually requires an audit of the final building; both rely on accurate self-reporting from the designers. Another difference between Green Globes and LEED is that in Green Globes the project is not penalized if a particular point is unavailable to the project. For example, LEED gives a point for a project built on a Brownfields site. This point counts toward the point total within the Sustainable Site category. If the location for the project precludes it being on a Brownfields site, there is no way for the project to regain that point and it may be unable to achieve the highest rating even if it is exemplary in all other respects. Green Globes’ points are adjusted based on project location. For these reasons, and also because some see LEED as increasingly driven by monetary interests within the USGBC, many prefer Green Globes.

    1. project management;
    2. site;
    3. energy;
    4. water;
    5. resources, building materials, and solid waste;
    6. emissions and effluents; and
    7. indoor environment.
  • CASBEE (Japan) and Green Star (Australia)
    Space precludes a detailed description of these in this essay. The interested reader is referred to [4] for more information on these two rating systems and also for more detail on LEED, BREEAM, and Green Globes.

Regardless of which of these rating systems is used, they have several characteristics in common. All account for– in varying degrees and using different algorithms and point systems– building energy usage, water usage, materials usage, ecological impacts and site considerations, and occupant well-being. None are perfect and each can be manipulated in ways that can actually produce a less green outcome, from an objective standpoint. For example, LEED has been criticized as stifling true design innovations by incentivizing designers to make certain design choices just to earn points needed to attain a higher level of certification, even if those design choices don’t contribute optimally to the sustainability of the overall design. Critics argue that truly innovative solutions are passed over because they don’t earn the designer or owner LEED points. To some extent, USGBC has attempted to address such criticisms by incorporating innovation points into the LEED system, but this is not a perfect solution. Ultimately, the effectiveness of any of these rating systems in ensuring an optimal building design lies in the skill and common sense of the design team employing them. There is no “one size fits all” solution to green building design; solutions are dependent on the location and use of the building, owner preferences, the budget, and other factors. The designer must optimize the sustainability of the building within the context of these other factors.

Building Material Reuse and Recycling:
Since the environmentally efficient use of materials is a parameter used in all the major green building rating systems described above, and since our subject painting directly speaks to the reuse of bricks, let’s briefly review how building material selection impacts the modern green building movement.

First, it is worth taking a moment to define the terms “reuse” and “recycling.” While sometimes mistakenly used interchangeably, they are technically different. “Reuse” of materials is taking a used building element—a brick, timber, flooring, doors, or other building materials or architectural elements and simply reusing them in another structure for the same purpose or similar purpose. Reuse can involve a cleaning or machining step (e.g. chipping mortar off bricks or resizing a timber using a saw), but does not involve reprocessing the material and remanufacturing it into another form. “Recycling” of materials is taking a used building element and reprocessing it such that it becomes raw material for a distinctly different finished product. A good example of a commonly recycled building element is steel. A steel beam from a demolished building can be sent to a steel mill, melted down, and reformed into another steel object, such as sheet goods, that can be used in automobiles or other products totally unrelated to the building process. In this context, the bricks in our subject painting are destined for reuse, rather than recycling.

A related point is that just because a building product is recycled or reused does not mean it is the most sustainable choice for a given building project. There are five generally recognized factors that can contribute to how green a building product is [5]:

  1. The product is made from “environmentally attractive” materials such as those that are salvaged, recycled, renewable, minimally processed or harvested in a sustainable manner.
  2. The product is “green” because of what it does NOT contain, for example treated lumber that doesn’t use conventional preservatives shown to harm the environment.
  3. The product reduces environmental impacts during construction, renovation, or deconstruction because of the way it is designed, e.g. certain types of modular building panels that reduce site disturbances during installation and which are easy to disassemble and reuse.
  4. The product helps to reduce negative environmental impacts during building operation, e.g. products that make the building very energy or water efficient and thereby increase overall building sustainability.
  5. The product contributes to a safer indoor environment within the building both for workers during construction and for occupants, e.g. low VOC paints that don’t release harmful fumes.

Sometimes a new product that contributes significantly to building energy efficiency is greener than a reused element that would contribute to a less energy efficient building. New windows versus reused windows are a good example. The new window, with high efficiency glass, would generally be considered the greener choice. Some material choices espouse more than one of the five factors listed. Generally speaking, the more of the five listed factors a single building material product espouses, the more likely it is to be the most sustainable choice for a given situation.

An integrated method for determining in an overall sense how sustainable a given building material choice is uses the Life Cycle Assessment (LCA) methodology. LCA is able to factor in the effects of multiple attributes—e.g., recycled content, high energy efficiency, low impact manufacturing process, etc.– and predict which material choices have lowest environmental impacts overall. LCA requires a detailed accounting of the raw material and energy inputs through out the life cycle of the product and also knowledge of emissions generated during product manufacture, transport, installation, use, and salvage/demolition. The life cycle of the product starts at the point where any raw materials needed to manufacture the product are mined or harvested and continues on until the building product is removed from the building many years later during demolition. The major downside to LCA is that we do not currently have sufficiently detailed databases quantifying raw material inputs, energy inputs, and emissions on many common processes and products. However, as research in the area of sustainable construction continues, such databases are growing over time.

One result of an LCA analysis on a building product is knowledge of that product’s embodied energy. Embodied energy is the total energy consumed in the acquisition and processing of raw materials, including manufacturing, transportation, and final installation. The lower the calculated embodied energy of a building product is, the lower its environmental impact. Reused products usually have lower embodied energy than newly manufactured products of the same type because the energy that went into the original manufacturing steps, (e.g. kiln firing a brick), do not have to be repeated before that product can be reused. It is interesting to note that according to the U.S. EPA [6], the U.S. manufactured over 8.3 billion clay bricks in 2001. Each brick has an embodied energy of approximately 4300 BTU [7]. Were we to reuse even a fraction of these bricks rather than simply manufacture them anew, the potential energy savings would be huge. At least in the case of bricks reuse makes tremendous environmental sense. One obstacle in the way of building materials reuse is the inability to match those who have materials that are available to be reused with those who wish to reuse them. This obstacle can be addressed more easily now than in the pre-Internet days through the development of searchable on-line materials exchanges such as the example shown in [8].

Final Thoughts:
A typical building has a life expectancy of 30 to 50 years or more, depending on its use, historical value, and other factors. Therefore, design decisions made today on a building project will influence energy consumption, water consumption, site ecology, and overall sustainability for decades. Arguably, wise design decisions are critical to the long term health of our environment. This brief overview of green building rating systems and of the sustainability of building materials is intended to increase awareness by users and consumers of buildings—homeowners and commercial developers alike—of the critical importance of the green building movement. By reclaiming used bricks from the rubble of World War II our Trümmerfrauen were employing aspects of sustainable design and construction, albeit because of the exigency of their circumstances, rather than due to any conscious efforts on their part to be “green.” Yet the Trümmerfrauen painting provides us with an interesting historical segue to better understanding the significance of the sustainable building movement in our own times.

References and Further Reading:

  1. Leick, R., Schreiber, M., and Stoldt, H.; “Out of the Ashes – A New Look at Germany’s Postwar Reconstruction,” Der Spiegel Online International, August 10, 2010. (http://www.spiegel.de/international/germany/out-of-the-ashes-a-new-look-at-germany-s-postwar-reconstruction-a-702856.html)
  2. Korkmaz S., Erten D., Varun Potbhare M.; “A Review of Green Building Movement Timelines in Developed and Developing Countries to Build an International Adoption Framework,” Proceedings of the Fifth International Conference on Construction in the 21st Century (CITC-V), May 20-22, 2009, Istanbul, Turkey.
  3. Ouroussioff, N., “Why Are They Greener Than We Are?”, The New York Times Magazine, May 20, 2007.
  4. Kibert, C.; Sustainable Construction—Green Building Design and Delivery, 3rd Edition, John Wiley and Sons, Inc., Hoboken, New Jersey, 2012.
  5. Wilson, A., “Building Materials: What Makes a Product ‘Green’?”, Environmental Building News, January, 2000.
  6. “Background Document for Life-Cycle Greenhouse Gas Emission Factors for Clay Brick Reuse and Concrete Recycling,” EPA530-R-03-017, November, 2003.
  7. “Sustainability and Brick,” Technical Notes on Brick Construction-TN 48, the Brick Industry Association, Reston, VA, June 2009.
  8. The Used Building Materials Exchange, http://build.recycle.net/exchange/.

Coming in Spring 2013 is an essay on sustainable farming practices, inspired by William Watson’s oil on canvas work, “Plowing with Oxen Teams.”