Home::Built Environment Sustainability::Frequently Asked Questions

To provide a bit more detail about built environment sustainability, here are some frequently asked questions:

• What does sustainability mean?
• Why should I care about sustainability? What's the big deal?
• How can I tell if my building is sustainable?

Note that full citations for all references cited in our answers are listed alphabetically in our master Reference List should you wish to learn more about any particular source. If you have any other questions besides those listed above, feel free to send email to one of our SFI staff and we'll do our best to point you in the right direction. Click here to go to the SFI staff page and send us an email.

To understand sustainability, the best approach is to think of it as the ability of something to be kept going or perpetuated into the distant future. As for the "something" which is to be sustained, the largest perspective is the whole of the human race and the environment in which we live. One source defines sustainability in the context of sustainable development as "development which meets the needs and aspirations of present generations without compromising the ability of future generations to meet their own needs" (WCED 1987).

Sustainability is a relationship, or balancing act, between factors which are constantly changing. Like "family values," everyone agrees that sustainability is a good thing, but no one agrees on what exactly it is, or even more significantly, how to achieve it and how to know when we have achieved it. In general, people agree on the primary focus of sustainability: not only must we sustain present generations of humans, but we have to be careful not to reduce options for future generations to survive and meet their own needs.

Let's look at one of the more easy-to-understand frameworks of sustainability: Munasinghe's Triangle. According to Munasinghe, there are three main sets of concerns which are important in examining sustainability at the philosophical level: environmental issues, social issues, and economic issues.

Social Issues
From the standpoint of social issues, a sustainable system meets the needs of its people without cutting the chances for other humans in the rest of the world to survive and prosper, and without reducing the chances of future humans to meet their own needs and aspirations. As such, a sustainable system is conscious of the impacts it has to the communities which surround it, and doesn't negatively impact those systems as it tries to meet the needs of its own humans. A sustainable system does, however, focus greatly on meeting the needs of the humans inside the system: not just basic human survival needs such as food, water, shelter, and air, but also other needs which contribute to greater human quality of life.

Economic Issues
From an economic standpoint, a sustainable system has to function within its economic constraints. Most systems have only finite economic resources with which to solve problems; for example, if a roof needs to be replaced, there is only so much money to do the job. Therefore, sustainable systems solve their own problems using the economic resources available to them. Sustainable solutions also take into consideration the whole life cycle of the system. For example, if that roof has to be replaced, there may be two different types of roof which can replace it. One of them may cost very little to install, but may need to be maintained every year at some cost and replaced every ten years. Another roof may cost twice as much to install in the first place, but may require no maintenance and may last for thirty years. From the long-term perspective of economic sustainability, the second roof would probably be more sustainable if the money can be found to install it. However, if you can only afford the first roof, then it may have to be the one you choose.

These three sets of issues, environmental, social, and economic, govern the decision making of a sustainable system according to Munasinghe's theory of sustainability. By considering each of these issues for a given system, you will help to ensure that the system can sustain itself into the foreseeable future.

To learn more about what sustainability means, check out the following SFI resources:

• APPENDIX B, DEFINITIONS DATABASE, CHAPTER 4, ORPHANAGE REPORT

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There are many reasons to care about sustainability in general, including:

It's the right thing to do.

With respect to buildings, we need to care about sustainability for three main reasons. First, we as humans need buildings to survive and prosper. Second, the way we currently create, operate, and dispose of buildings has significant negative impacts on ecosystems, resource bases, and human occupants, and is therefore unsustainable. Third, those of us who change the way we make buildings now will have a significant competitive advantage over the rest as resource bases and ecosystems are depleted and degraded, and as stakeholders of buildings increasingly use legal avenues to receive compensation for the negative effects buildings have on them. Let's look at each of these reasons in turn.

We need buildings to survive and prosper.
In nearly all environmental contexts found on Earth, the built environment is an essential part of the infrastructure necessary for human survival. Buildings provide shelter from adverse climate conditions such as rain and snow, ambient temperature ranges outside human comfort levels, and threatening weather conditions. They also afford privacy and security from a variety of dangers, including predatory and pest animals and malevolent humans (Allen 1980). In addition to these roles which contribute to basic human survival, built facilities serve other purposes which help to expand the quality of human life beyond mere biotic survival, including their role as infrastructure for activities such as:

• Collection, treatment, and/or storage of solid, liquid, and gaseous waste
• Provision and distribution of pure water
• Processing and distribution of agricultural products into food
• Manufacturing and distribution of other products used by humans

The way we presently create, operate, and dispose of buildings is unsustainable.
Built facilities are complex technological systems that meet critical human needs, persist over significant lengths of time, and involve multiple diverse stakeholders. Their interrelations with the technological and ecological systems that surround them have significant impacts on those systems. Built facilities are not independent of these systems; they could not exist without complementary technological and ecological systems to provide sources of matter and energy as inputs, and sinks, consumers, or storage for system outputs. The primary links between built facility systems and other technological and ecological systems are via the flows of matter, information, and energy across the boundaries of the system. The following figure (from Pearce 1999) shows examples of flows into and out of a built facility, and how they relate to its technological and ecological context.

The impacts of these interactions have not always been noticeable on the scale of individual facilities, but their cumulative effects on the planet over time have been increasingly well documented. For example:

• Buildings are responsible for over ten percent of the world's freshwater withdrawals, twenty-five percent of its wood harvest, and forty percent of its material and energy flows (Roodman & Lenessen 1996).
• 54% of U.S. energy consumption is directly or indirectly related to buildings and their construction (Loken et al. 1994).
• 30% of all new and remodeled buildings suffer from poor indoor environments caused by noxious emissions, off-gassing, and pathogens spawned from inadequate moisture protection and ventilation, resulting in $60 billion annually in lost white-collar productivity from Sick Building Syndrome (SBS) in the U.S. alone (Kibert et al. 1994).
• Nearly one-quarter of all ozone-depleting chlorofluorocarbons (CFCs) are emitted by building air conditioners and the processes used to manufacture building materials (Energy Resource Center 1995).
• Approximately half of the CFCs produced around the world are used in buildings, refrigeration and air conditioning systems, fire extinguishing systems, and in certain insulation materials. In addition, half of the world's fossil fuel consumption is attributed to the servicing of buildings (Zeiher 1996).
• The average household is annually responsible for the production of 3,500 pounds of garbage, 450,000 gallons of wastewater, and 25,000 pounds of CO2 along with smaller amounts of SO2, NOX, and heavy metals (Barnett and Browning 1995).
• Lighting accounts for 20-25% of the electricity used in the U.S. annually. Offices in the U.S. spend 30 to 40 cents of every dollar spent on energy for lighting, making it one of the most expensive and wasteful building features (Energy Resource Center 1995).
• The construction industry is responsible for 8-20% of the total Municipal Solid Waste (MSW) Stream, 14% on average (Tchobanoglous et al. 1993).

These cumulative impacts have resulted in increased attention to the role played by built facilities and infrastructure in the problems of natural resource depletion and degradation, waste generation and accumulation, and negative impacts to ecosystems. Since built facilities are a major direct and indirect contributor to these problems, they now face increasingly restrictive environmental conservation and protection laws and regulations, international standards to address environmental quality and performance, and substantial pressures from civic groups, environmental organizations, and citizens. As a result, facility stakeholders face new, complex and rapidly changing challenges imposed by these laws, regulations, standards, and pressures at all life cycle stages.

For example, negative impacts to natural ecosystems have begun to enter into decision-making in the construction industry. Forced by environmental legislation such as the National Environmental Policy Act of 1970, many U.S. projects now require an Environmental Impact Assessment of the project to be completed before construction can proceed. Still, however, many project planners, designers, and contractors see environmental considerations as an obstacle to be overcome rather than a way to achieve benefits for themselves and others (Kinlaw 1992). Many actions taken to mitigate environmental impact of projects are typically only applied as end-of-the-pipe measures, not changes to the environmentally damaging processes themselves (Liddle 1994). These traditional strategies of mere environmental regulatory compliance or reactive, corrective actions such as mitigation or remediation have proven to be consistently costly, inefficient, and many times ineffective (Vanegas 1997).

Other triggers for change center around resource depletion and degradation. For example, many municipalities have adopted energy codes to promote energy efficiency in new facilities. While not widely enforced, these codes nonetheless represent an evolutionary step for the construction industry. In other cases, increased scarcity of resources such as dimensional lumber have forced the industry to seek alternatives to traditional materials, including engineered wood products, steel framing, recycled plastic lumber, and stress-skin panels. These products make use of materials formerly considered to be waste, including sawdust, post-consumer plastic, and wood pieces too small to be otherwise incorporated as structural members, and result in products that are structurally superior to the materials they replace. Alternative framing practices have also become more commonplace as constructors seek to minimize the use of raw materials. A positive side effect of some of these new trends is increased energy efficiency due to decreased thermal bridging and integrated insulation (BSC 1995).

A third trigger for change is the increasingly noticeable impacts of the built environment on human health. Many humans spend most of their time indoors, nearly 90% of an average day (Kibert et al. 1994). Building-related threats to human health include the carcinogenic properties of asbestos and the neurologically damaging effects of lead-based paint. Yet these products were common components of buildings during the period between 1950 and 1970. More recent evidence supports the carcinogenic effect of low-level electromagnetic radiation, which is generated by all electrical appliances (Rousseau & Wasley 1997). Some individuals are highly sensitive to irritants and/or toxins such as off-gassed volatile organic compounds (VOCs), formaldehyde from adhesives and fabrics, and molds, bacteria, and dust accumulating in and resulting from building products (ibid.). The cleaning and maintenance products used during facility operation, including pesticides, solvents, and chlorine, present another set of irritants that cause reactions in an increasingly large portion of the population. Rousseau and Wasley describe the trend:

The body absorbs an alarming number of these agents, and some accumulate for long periods causing toxic or immune-like reactions. Others mimic chemicals which regulate body functions, causing Ôerror responses.' Testing requirements for new chemicals may be rigorous, but it is impossible to anticipate all of their potential long-term effectsÉThe financial gain from successful new products makes them very attractive to develop, and creates political pressure to approve them for sale. It is sobering to think that chlorofluorocarbons, DDR and PCBs were all considered Ômiracle chemicals' when they were introduced. (1997, p. 14)

Given the complex combinations of materials and chemical products being incorporated into built facilities, the potential of buildings to have negative impacts on human health is significant, and the number of lawsuits relating to sick building syndrome is rising. The quantity of potential irritants and toxins is growing rapidly with the proliferation of synthetic chemicals present in almost every product used by humans. Thus, threat to human health is a third significant category of triggers that reflects the need for change in the way built facilities are created and operated, along with the building technologies, systems, products, and materials used within them.

Those of us who change the way we make buildings now will have a significant competitive advantage.
All of the triggers described above represent significant trends in the construction industry that will eventually permeate every aspect of the industry. Builders and other stakeholders who are proactive regarding these trends will not only be able to offer their clients superior buildings, but also will avoid regulatory penalties, trade restrictions, and other costs in both the short and long term.

Sustainable construction is an approach to creating facilities with the goal of meeting the needs and aspirations of humans while minimizing negative impacts to the resource bases that provide goods and ecosystems that provide services to meet those needs. From a life cycle perspective, sustainable construction may yield economic benefits to decision makers while at the same time protecting the environment and moving toward a higher level of quality of life for stakeholders and non-stakeholders alike (Kinlaw 1992). For example, Schmidheiny (1992) writes:

...environmental concerns become not just a cost of doing business, but a potent source of competitive advantage. Enterprises that embrace [sustainable development] can effectively realize the advantages: more efficient processes, improvements in productivity, lower costs of compliance, and new strategic market opportunities.

Liddle (1994) echoes this sentiment:

Sustainability will impact the construction industry in a number of ways: polluting processes and materials used in construction will become more expensive, new markets will be created for energy efficient buildings, for manufacturing firms looking to reduce their pollution, and for satisfying increasingly environmentally concerned clients and public; new sources of funding for projects with environmental benefits will become available; finally, there will be increased traditional (infrastructure) projects owing to an emphasis on investment.

While the differences between traditional and sustainable construction can be radical, the forces of social and economic change are increasingly eliminating the differences. Whereas traditional construction focuses on cost, performance, and quality objectives, sustainable construction will add to these criteria minimization of resource depletion and environmental degradation, and creating a healthy built environment (Kibert 1994). Sustainable construction approaches each project with the entire life cycle of the facility in mind, not just the initial capital investment. Accordingly, decision makers must evaluate the long-term as well as short-term impacts of their decisions on both local and global environments. Project stakeholders who take a sustainability approach to construction will be rewarded with reduced liability, new markets, and an Earth-friendlier construction process, which will help future and current generations to achieve a better quality of life (Kinlaw 1992, Liddle 1994).

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Many systems have been developed, in the U.S. and elsewhere, to assist with rating or measuring the sustainability or "greenness" of a building. For the most part, these systems are based on encouraging best practices and promote a step-by-step, incremental process toward a sustainable built environment. The outcome of using the system may still not be a truly sustainable building. For your building to be truly sustainable, it must meet the following criteria over its whole life cycle:

• It must not use more resources than are actively being regenerated, i.e., it must not contribute to the degeneration of the world's resource bases.
  This criterion means that whatever matter and energy resources are being incorporated into your building or used for its construction, operation, maintenance, rehabilitation, or eventual disposal must be offset in some way such that the net amount of resources available does not decrease. This may be done by avoiding the use of resources in the first place (e.g., using an existing building instead of building a new one), using only resources that are being sustainably harvested (e.g., wood from forests that are being replanted at a rate that offsets timber harvests), or taking active steps to regenerate resource bases that are being unsustainably harvested (e.g., returning stormwater to local aquifers to offset water being taken from those aquifers to operate the building). For nonrenewable resources such as metals, this criterion means recovering such materials from waste streams rather than further depleting untapped reserves.

  In general, sustainable use of resources means that the building should primarily rely on solar energy and its manifestations through biological and/or geophysical processes during operation, since these are the only truly renewable resources available to us within the fundamentally closed system of Earth. Ideally, the building would meet all of its operational needs using resources on site, such as localized power production, complete wastewater recycling using living systems, supplemented by rainwater harvest as necessary, and reliance on available site materials for ongoing operation and maintenance of the building.

  In reality, this is rarely the case. The advanced technologies upon which we rely for our buildings nearly all come from other places and are the product of complex manufacturing processes which themselves require intense inputs of matter and energy. To offset these impacts for which our buildings are indirectly responsible, we must take steps to regenerate resource bases beyond the scope of our building's operational requirements. For example, some buildings become net energy producers using on-site renewable energy sources such as photovoltaic-produced solar energy, hydroelectric power, or geothermal systems. Other building stakeholders offset their building's resource use by assisting other buildings in saving energy, water, or materials through retrofits with more efficient systems. Still others actively replant forests to replace timber taken from them, or promote recycling and resource recovery to reclaim nonrenewable materials from the waste stream to offset their use. These and other strategies can help to make a building sustainable with respect to resource use, i.e., having no (or positive) net impact on the world's resource bases.

• It must not degrade ecosystems more rapidly than they can absorb negative impacts without change, i.e., it must not contribute to the degeneration of the world's ecosystems.

• It must meet the needs, aspirations, and expectations of its stakeholders, i.e., it must prevent them from doing other, more unsustainable things to meet their needs.

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