Complexities of Sustainability

LEED as the Definition of Sustainability
Can LEED Survive the Carbon-Neutral Era (Metropolis, November 2007) discusses the growing acceptance of the US Green Building Council LEED rating system while also considering future challenges to its relevance:

• USGBC claims 40,000 LEED-accredited professionals. The organization has certified only roughly 1000 buildings since its inception.
• A recent study by construction consultant Davis Langdon claims that LEED-certified buildings, at least up to the Gold certification level, need not cost more than conventionally designed buildings. Fiona Cousins of ARUP New York estimates it can cost $100,000 in service fees to document building performance for LEED.
• Until June of this year, buildings could achieve LEED certification without receiving any energy performance points associated with reductions in carbon emissions.
• ASHRAE, in conjunction with USGBC and others, is promoting its Advanced Energy Design Guides which target energy savings of 30% over current national  standards. ASHRAE intends to introduce similar mandatory standards by the year 2012. ASHRAE and the AIA are proposing national legislation that would require new buildings to be fully climate-neutral by the year 2020.

The article also discusses the pros and cons of the LEED "checklist" methodology for defining sustainability, in contrast to more ntegrated approaches to sustainable building design. And the article speculates on the possibility of LEED's broad definition of sustainability, which includes considerations of site and community development, materials and resources, and indoor air quality, being preempted in the future by the need to focus more narrowly on the conservation of water and energy.

Separately, The Battle for Green Building (Springfield Business Journal, 12/11/20067) discusses the Green Building Initiative's Green Globes sustainable building certification program, an alternative to the better know LEED. Though there are many similarities between these two programs, Green Globes is reportedly distinguished by its pending certification by the American National Standards Institute, and its lower implementation cost than LEED.

PVC as a Sustainable Material
The USGBC's February 2007 Assessment of the Technical Basis for a PVC-Related Materials Credit for LEED is the that organization's final report on the contentious issue of the use of PVC materials in building construction.

USGBC has been considering this issue since at least the year 2000. The Assessment looks at four common PVC applications: siding, drain/waste/vent piping, resilient flooring, and window frames. Each is compared with common alternatives, for example in the case of siding, with aluminum, wood, and fiber-cement. Materials are evaluated on a number of bases:

• Conventional life-cycle assessment in which all the resource and pollution inputs and outputs associated with the material-- beginning with its harvesting or extraction and ending with its reuse or disposal at the end of its service life--are considered. Impacts on both human health and the environment are included.
• Extended end-of-life analysis in which potential PVC dioxin emissions from backyard burning and accidental landfill fires are considered. Given the large uncertainties in the data for this scenario, upper, middle, and lower range estimates were evaluated.
• Risk assessments of the adverse human health effects due to exposure to toxic compounds generated throughout the life cycle of the materials.

The conclusion: No single material shows up as the best across all human health and environmental impact categories, nor as the worst.

The assessment's results resist simplistic conclusions. Material rankings vary depending on how environmental and human health impacts are prioritized. In other words, a choice of one material over another may benefit human health while increasing adverse effects for the environment, or vice-versa. Rankings also vary with the product category. Only in the resilient flooring category do PVC products rank consistently higher in both adverse human health and environmental effects than alternative materials (linoleum and cork).

Meanwhile, Schwarzenegger Bans PVC Additive In Toys (Healthy Building Network, October 25, 2007) reports that, despite claims made by the Vinyl Institute regarding the safety of PVC in children's toys, the state of California has passed legislation prohibiting the use of phthalates, a PVC plasticizer, in products intended for babies and children under three years of age. The article goes on to state:

Like the human carcinogens vinyl chloride and dioxin, phthalates are uniquely associated with PVC. It is this triple threat from PVC that distinguishes it as the worst plastic for environmental health and green building. Regrettably, there are still few restrictions on the use of vinyl in green buildings.

Evolving Measures of Material Sustainability
Shedding Light On The Pharos Project (Eco-Structure, December 2007) describes the Pharos Project, an ambitious building products rating program under development by the Healthy Building Network.

The Pharos Project is touted as a database of building materials intended to allow a more comprehensive and sophisticated evaluation of the sustainable attributes of materials than is currently offered by other rating systems. Its unique framework covers a broad range of health, environmental sustainability, and social justice criteria.The Project will also host a Wiki and online forums.

A visit to the Project's web site leaves one questioning whether the Project is alive and well. The most recently dated content appears to be from November of 2006. According to Eco-Structure, the next working version of the Project is scheduled for release in the spring of 2008.

Measures of Sustainable Buildings
Energy Performance Data Largely Lacking (ENR, November 12, 2007) reports that, despite the attention being given to green building design, there is a lack of standards for collecting and analyzing building energy performance data, and, though newer buildings may be designed to be more energy efficient than older buildings, building energy use overall continues to climb:

• According to the U.S. Department of Energy, commercial buildings consumed 18 quads (18 quadrillion BTUs) in 2004, and are projected to consume 25 quads--almost a 40 percent increase--by the year 2030. The largest part of this jump is attributed to increased use of electrical equipment and the increased cooling loads that result.
• Between 1980 and 2000, energy use per square foot in commercial buildings increased by roughly 25 percent.

LEED certification does not necessarily correlate with reduced building energy consumption. On the one hand, Seattle's LEED-Silver Alley24 mixed-used development, completed in 2006, is reportedly close to achieving a 50 percent targeted reduction in CO² emissions. On the other hand, Seattle's new City Hall, also LEED-Silver, completed in 2003, is separately reported as consuming significantly more energy than the larger, older building that it replaced.