Green Building: Fad or Future?
June 2008According to the U.S. Energy Information Administration, buildings are the single largest contributor to global warming, accounting for almost half of total annual U.S. energy consumption and carbon dioxide emissions.
When it comes to green building, it’s first and foremost about reducing both energy consumption and carbon dioxide emissions.
The What: Leadership in Energy and Environmental Design (LEED)
LEED is a certification program and benchmark for the design, construction and operation of high performance green buildings. It provides both building owners and operators with the tools they need to measure their buildings’ energy performance.
LEED also promotes a whole-building approach to sustainability by recognizing construction achievement in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.
The Why: Our Planet
Planetary ills—resource depletion, mounting toxic waste, deforestation and, most importantly, global warming—have, over the past two decades, made their way from seldom heeded mutterings of environmental scientists and tree-huggers, to grave front page and television news, as in the recent December 2007 Bali Accord, where 186 countries agreed and acknowledged that, no, all is not well with the third planet from the sun.
Anyone who cares to study and reflect on the facts is bound to agree: We have to do something. And we have to do it now, before we deplete our planet. The question is: do what, exactly?
Depending upon which statistic you find most accurate, it is generally agreed that buildings consume between 40 and 48 percent of all global energy, roughly 40 percent of all virgin material—this while they produce 40 percent of all carbon dioxide on the planet, along with roughly 40 percent of all landfill waste in the United States.
As the single largest contributor to human-caused global warming (buildings account for approximately 48 percent of total annual U.S. energy consumption and 43 percent of total annual U.S. greenhouse gas emissions), the building industry finds itself dead center on this issue.
It’s Coming at Us Fast
Even though a majority of U.S. contractors rarely encounter or have yet to encounter "green” specs as part of their day-to-day bid documents, in greener parts of the country such as New England, New Mexico, Oregon and California, some are involved in green bid specs, and projects seeking LEED certification, 20 to 60 percent of the time. And, all contractors surveyed agree: The green movement is not a fad, it is not going away.
One contractor summed it up in five words: "It’s coming at us fast.”
Green building—our industry’s response to these planetary ills—is no longer just a nice thing to know more about, but of vital importance to the survival of not only the contractor, but of Earth.
Consequently, federal and state agencies no longer merely suggest green designs and implementations, they prescribe them. Likewise, large corporations with huge building portfolios, like Starbucks, are concerned about their eco-footprint, and now they too have begun to focus on sustainable design and construction.
Clearly, more and more buildings are going to seek LEED certification, more and more owners are going to want to do—or want to be seen to do—the right thing environmentally, whether for altruistic or PR reasons. Before long, the subcontractor who will be awarded the job is the subcontractor who is up to speed on, and can perform in, the green building environment.
Ten years from now, or 20 at the most, as environmental awareness filters down into law and building codes, building green will have progressed from voluntary effort to legislated requirement.
The Who: U.S. Green Building Council
While there are now many green movements afoot, both here and abroad, spearheading the green building effort in the United States is the U.S. Green Building Council.
Originally formed in 1993 by developer David Gottfried and environmental lawyer Michael Italiano, USGBC set as its goal the creation of a workable sustainability rating system. To achieve this, USGBC formed LEED in 1995, and for the next three years the LEED committee considered—and rejected—a host of ratings models, including the Canadian Green Builder program and the United Kingdom’s promising Building Research Establishment Environmental Assessment Method system.
After a number of starts and stops, in late 1998, the USGBC membership finally approved LEED Version 1.0, and within months, a pilot program was launched with the support of the Federal Energy Management Program.
LEED had arrived.
The pilot did, however, expose some shortcomings of LEED 1.0. Several of the 40 earnable credits were found to be either too strict or to already be standard practice.
Back to the drawing board.
The result was LEED 2.0, which was approved by the USGBC membership in March 2000. This version of LEED expanded the attainable credits from 40 to a maximum of 69. Also, the range of the various categories—Certified, Silver, Gold and Platinum—were expanded, and the resource guide was revised and upgraded.
The LEED rating system has, in a comparatively short time, already begun to transform the $315 billion U.S. design and construction industry.
As an example, the General Services Administration now requires all new GSA construction to seek LEED Silver status; the Naval Facilities Engineering Command has incorporated LEED into instructions for new Navy buildings; other federal entities, such as the Army and the Air Force, are adapting LEED to their own requirements.
Major corporations—Ford, Sprint, Steelcase, PNC Financial Services and Toyota, to name a few—have embraced LEED and sustainable design. Foundations are coming aboard. Municipalities, counties and states are also either adopting LEED or reworking it to meet local or regional needs.
Many colleges and universities have made LEED a standard for new construction; and even some speculative real estate developers have embraced the LEED process—as with Four Times Square, in Manhattan, and EcoWorks at Southlake, outside Kansas City, Kan.
Although LEED is not without its flaws, its simple structure—based on a system of points to be achieved for various criteria met—has gained it a strong following, and it is now the most widely accepted program of its kind in the United States.
The How: The LEED Rating Systems
The stated goal of LEED is to transform the building industry by introducing rating systems that reflect scientific knowledge, leading-edge architectural and engineering design approaches, and best practices in construction and development.
LEED certification is divided into six different rating systems:
• LEED-NC for New Construction (and major renovations).
• LEED-CS for Core and Shell (office buildings and other speculative projects).
• LEED-CI for Commercial Interiors (remodels).
• LEED-EB for Existing Buildings (continuing building operation).
• LEED-ND for Neighborhood Development.
• LEED-H for Homes.
The dominant of these systems is LEED-NC, which comprises 77 percent of all certified projects and 79 percent of all registrations.
LEED Points—How They Are Awarded. The first four LEED ratings systems above (NC, CS, CI and EB) are broken down into six categories of evaluation: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and Innovation and Design (LEED-ND and LEED-H have their own distinct areas of evaluation).
Each of these categories is in turn itemized as to specific targets of design and construction, which, when achieved and documented, are awarded points commensurate with the contributing factor of that item.
LEED for New Construction (LEED-NC). LEED-NC rating system contains 32 categories of environmental design and energy concerns in the mentioned areas of site development, water efficiency, energy efficiency, material use/reuse and indoor environmental quality, with a total of 64 attainable points; add to that 5 possible innovation and design bonus points, for a total of 69.
To attain Certified rating under the LEED-NC system, a project must reach a minimum of 26 points; to attain a Silver rating, it must reach 33 points; for Gold, the number is 39; and for Platinum, the bar is raised to 52.
To certify, each project requires detailed documentation that must be reviewed and evaluated by an independent auditor.
It is a testament to the workability of the LEED process that projects that have attained a LEED Certified rating tend to be 30 percent or more energy efficient, tend to use 30 percent or less water, and tend to have healthier indoor air, with more daylight and better outside views for their occupants, than buildings that merely measure up to current code.
The How: Ceilings and Walls
While the LEED rating systems apply to all aspects of building construction, and to all trades, points are mostly earned through the combined efforts of many diverse contractors.
The wall and ceiling industry does, in fact, have a significant share in this effort, and an analysis of where and how the wall and ceiling contractor specifically contributes to LEED certification may be of use.
Walls. Exterior and interior walls can and do contribute significant LEED certification points in the categories of Energy and Atmosphere, Materials & Resources and Indoor Environmental Quality.
Energy and Atmosphere. Optimized Energy Performance: Exterior walls utilizing either exterior insulation and finish systems or insulated concrete forms can, through improved insulation, contribute as many as 10 points (if the energy performance is shown to improve 42 percent or better). This is a large block of points, constituting more than a third of the 26 points needed for basic LEED-NC certification.
Materials & Resources. Construction Waste Management: By redirecting recovered resources back to the manufacturing process, and by redirecting reusable materials to the appropriate sites—such as properly sorting on-site waste into designated containers—the wall contractor can contribute 1 or 2 LEED points to the project.
Recycled Contents: By using 10 to 20 percent recycled products—such as concrete with high potash contents—the wall contractor can again contribute 1 or 2 LEED points to the project.
Regional Material: By obtaining regionally processed or manufactured material, the wall contractor can contribute 1 or 2 LEED points.
Indoor Environmental Quality. Low-Emitting Materials: By using low-emitting adhesives and sealants the wall contractor can contribute 1 or 2 LEED points to the project.
Thermal Comfort: Through the use of ICF or EIFS, or other high-quality insulation material, the wall contractor can contribute 1 LEED point to the project.
Ceilings. Interior finishes, such as ceilings, can help accrue points in four different categories: Materials & Resources, Indoor Environmental Quality, Energy and Atmosphere, as well as in the special Innovation in Design category.
Energy and Atmosphere. Optimize Energy Performance: To aid in energy cost savings and reduced lighting power density, high light reflectance (LR) ceilings and systems provide an optimum level of luminance with fewer fixtures. The number of LEED points awarded for such improvements depends on the overall level of energy efficiency attained, but can contribute to as many as 10 points.
Materials & Resources. Construction Waste Management: By redirecting recovered resources back to the manufacturing process, and by redirecting reusable materials to the appropriate sites—such as properly sorting on-site waste into designated containers—the ceiling contractor can contribute 1 or 2 LEED points to the project.
Recycled Contents: Acoustical ceilings normally contain high levels of recycled content either in the form of pre-consumer (post-industrial) or post-consumer waste. The amount of recycled content varies by product, so check with the manufacturer for exact percentages and appropriate documentation. The ceiling contractor can contribute 1 or 2 LEED points to the project in this category.
Regional Materials: If a minimum of 20 percent of the construction materials and products the ceiling contractor uses for the job are manufactured regionally (within a radius of 500 miles), he can contribute 1 or 2 points to the project.
Indoor Environmental Quality. Daylight and Views: If the ceiling contractor achieves a minimum glazing factor of 2 percent in at least 75 percent of all regularly occupied areas and provides daylight redirection and/or glare control devices to ensure effective daylight reflection, he can contribute 1 point to the project.
High light reflectance (LR) ceilings can aid in extending daylight into a space. A typical acoustical ceiling reflects approximately 75 percent of the light striking the surface, while a high LR ceiling is engineered to reflect up to 90 percent of the light striking the ceiling surface.
Finishes. Finishes offer a great opportunity to make the project environmentally friendly, and so can earn LEED points. Low-VOC (Volatile Organic Compound) paints, natural plasters on walls, certified wood, recycled foam padding, all contribute.
Specifically, gypsum boards, acoustical ceilings, wall coverings, and painting and coating, can all contribute directly to a project’s LEED points, primarily in the Materials & Resources and Indoor Environmental Quality categories.
Materials & Resources. Construction Waste Management: As with the ceiling contractor, by redirecting recovered resources back to the manufacturing process, and by redirecting reusable materials to the appropriate sites—such as properly sorting on-site waste into designated containers—the contractor working finishes can contribute 1 or 2 LEED points to the project.
Recycled Contents: Acoustical ceiling tiles and gypsum boards can contain high levels of recycled content. Although the amount of recycled content varies by product, the contractor can contribute 1 or 2 LEED points to the project in this category.
Regional Materials: If 20 percent or better of the material and products the contractor uses on the job are manufactured regionally (within a radius of 500 miles), he can contribute 1 or 2 points to the project.
Indoor Environmental Quality. Low-Emitting Materials: By using low-emitting adhesives and sealants, or no adhesives or sealants at all—for example, screw-attaching all gypsum—the contractor can contribute 1 or 2 LEED points to the project.
Framing. Steel is the world’s—and North America’s—most recycled material. As a consequence, the steel used in steel stud framing typically contains 23 percent pre-consumer (also called post-industrial, meaning the reintroduction of manufacturing scrap—such as trimmings, defective products, byproducts, etc.— back into the manufacturing process) and 7.3 percent post-consumer (meaning what the consumer discards after use, what we think of as consumer waste) recycled contents.
When LEED calculates the percentage of recycled material, it takes into account the full post-consumer recycled percentage plus half the post-industrial recycled percentage.
Typically, then, for LEED purposes, steel stud framing contains 18.8 percent recycled material, that is: the full 7.3 percent post-consumer plus half of 23.0 percent (11.5 percent) pre-consumer = 18.8 percent.
This percentage well exceeds both the 5 percent and 10 percent LEED goals, and so can contribute 2 LEED points to the project.
The basic category of point contribution for the wood framer is the use of wood products that have been certified by the Forest Stewardship Council as reclaimed or as managed according to FSC’s guidelines.
These guidelines evaluate forest management practices in three areas: sustainable harvest, ecosystem health and community benefits. Biologists, ecologists and foresters examine and measure the impact of forest practices on wildlife and their habitat, water quality, soil and plant conservation, natural forest sustainability and biodiversity, visual aesthetics, and the total ecological integrity of the forest.
Through the use of FSC or similarly certified wood, the framing contractor can contribute 1 LEED point to the project.
EIFS. EIFS can contribute to LEED points in the Energy and Atmosphere, Materials & Resources and Indoor Environmental Quality categories:
Energy and Atmosphere. Optimize Energy Performance: An airtight, well-insulated building enclosure has a significant effect on the energy consumption of a building. A 2005 National Institute of Standards and Technology study showed that use of a structural air barrier can reduce energy consumption of a building by as much as 40 percent. In addition, the overall energy performance of a building and its interior environment can be greatly improved by placing the insulation on the outside of the building, thus minimizing thermal bridging across the structural elements of the wall construction.
EIF systems featuring waterproofing/air barrier assembly and a protective blanket of exterior insulation can provide energy savings and protection from moisture intrusion in a cost-effective cladding, and can contribute up to 10 LEED points to the project.
Materials & Resources. Building Reuse: Recoating an existing building or applying new insulated wall cladding over existing cladding are both strategies that can be used to repair, protect, and provide an updated aesthetic design to the structure. In this category, EIFS can contribute 1 or 2 points to the project.
Construction Waste Management: EIFS products are typically packaged in bags or pails that can be recycled through traditional waste management programs. EIFS can contribute 1 or 2 points in this category.
Recycled Content: Depending on the level of recycled material in the EIFS product, its use can contribute 1 or 2 points to the project.
Indoor Environmental Quality. Low-Emitting Materials: Paints, coatings and primers with VOC content less than 50 g/L comply with this LEED requirement. Most EIFS products meet these criteria and so can contribute 1 LEED point to the project.
Thermal Comfort: Through the use of ICF, EIFS or other high-quality insulation material, the wall contractor can contribute 1 LEED point to the project.
By providing well insulated and energy efficient walls—both external and internal; by use of recycled materials and by proper recycling at the site; and by implementing high LR ceilings, the wall and ceiling contractor can, and should, make a major contribution to every LEED certified project.
Twenty years from now, though some say sooner, green principles will be part of building codes around the nation, as well as mandated by state and federal law.
In the intervening years, green building will graduate from a sometimes more costly alternative to prescribed necessity, and the contractor who prepares himself or herself for this future—the contractor who understands the what, why and how of green building—will fare the best.
The point is: LEED is no fad. And recognizing this, AWCI will soon publish a white paper—upon which this article is based—to guide you through the green landscape. Look out for it next month.
Los Angeles-based Ulf Wolf writes for the construction industry as Words & Images.