January-February 2010

Gold, Silver, Platinum …Green

USGBC implements new LEED water incentives to address a chronic scarcity of times.

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Photo: City of San Jose

By David Engle

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What started in 1998 with a tiny, all-volunteer crew cooking up a recipe for green-building design has, in just a dozen years, morphed into a national network of more than 350 earnest advocates and environmental professionals forming dozens of local green-building standard-supervising committees.

Meanwhile, the prototype design model is long gone, surpassed by a six-pack of others. Each focuses on sub-specialties—e.g., green design, green construction, green operation, etc.—deemed necessary in their own right, to ensure that every aspect of architecture and operation henceforth will demonstrate what is called “Leadership in Energy and Environmental Design”—better known, of course, by its acronym, LEED.

And lately, one of the six is devoted entirely to water efficiency—a sign of evolving knowledge and also of changing times.

LEED also revises itself on a recurring basis: new versions have come forth periodically like popular software upgrades, advancing from a 1.0 to a 2.0, then 2.2, and now, as of mid-2009, LEED 3.0.

Two “flavors” are recognized now: LEED for new construction, and another for renovated existing buildings (“LEED-EB”).

The purpose of it all is, of course, to normalize notions of resource conservation and sustainability, and to make these as fundamental to building praxis as laying a firm foundation or sealing a sturdy roof. In the LEED-seeking quest, which is overseen by the US Green Building Council (USGBC), architects try to win points on a scoring system by incorporating the above, peer-recognized green guidelines. After mastering the often time-consuming and exacting steps, project teams gain recognition for attaining basic certification, or, in most cases, winning higher distinction for “silver,” “gold,” or “platinum” green-ness.

Scoring emphasis is driven mainly by things like using recycled/recyclable construction materials and, above all, for energy conservation. However, water efficiency is also gaining much greater attention and earning a proportionally higher scoring weight. In LEED version 2.0 for example, a maximum of 100 base points were possible across all categories (with some bonuses), of which 10 points could be earned in three water-specific areas: for water use reduction, water efficient landscaping, and innovative wastewater technologies. That’s considerably more attention than was given in version 1.0.

Photo: City of San Jose
San Jose City Hall was the first municipal building and first city hall in the country to “go platinum” under LEED-EB.

Concerning the new wrinkles found in 3.0 from a water standpoint, “We have now instituted a prerequisite for water use reduction that didn’t exist before,” says USGBC vice president of technical development Brendan Owens. “Previously, you could win the cachet of the LEED label without dealing with water at all; now, every would-be green edifice must achieve at least a 20% reduction in water usage against a baseline—just to get in the door to apply.

More points can be racked-up in increments—one for every 10% in further water reduction.

The new standard also takes cognizance of differences between, say, rainy climes where they don’t fret over water, and the arid Southwest, where they do. Previous LEED versions ignored such factors, but now, says Owens, “We’ve instituted a mechanism that allows project teams and chapter networks to identify the issues that are most important to their projects, based on region.” He’s anticipating that resulting scoring weights will be adjusted here and there to incentivize water savings, starting soon.

Winning Points for Fixtures
As for actually running up the tally for faucets and flushers, etc., the principles are simple. “Most people who are fluent in water savings would easily determine what they want to try to accomplish—without the need for doing some kind of extensive analysis,” says Owens.

A documentation form from USGBC outlines “what it is that we’re going to be asking project teams to prove and show us when they are submitting for project certification,” he adds. These and other guidelines can be freely downloaded from www.usgbc.org.

Calculations begin with establishing baseline water usage. Next, to determine the savings impact of measures, charts are provided that show flow rates and performances of assorted manufacturers’ plumbing goods. Lastly, a totaling of the net savings, followed by figuring the percentage improvement this represents, yields the point(s) to be won.

Regarding water closet hardware selections: USGBC doesn’t set forth one “best available” standard, but leaves choices up to the architects. Owens explains, “We really have been purposefully ‘technology agnostic’ as to how project teams can go about achieving those percent improvements. So, if a project team wants to use dual-flush toilet, waterless urinals, or high-efficiency toilets, or wants to use recaptured rainwater to flush toilets, we’ve been liberal in our interpretation of what are the best ways of going about accomplishing those goals, in favor of having a performance target that teams strive for.”

Technology options naturally run the gamut from costly and exotic apparatuses like stormwater collection system—which may be tough to cost-justify—to low-flow toilets, lavatories, and faucet aerators, that are now virtually de rigeur; the latter coming up “most often” in applications, especially “as product performance is still rapidly improving,” he notes.

There’s also budget-driven competition between LEED categories. Thus, for example, rooftop water collectors may lose out to rooftop solar panels. This is actually not at all uncommon, he says. So in recognition of this challenge, and in order to reduce such dilemmas, USGBC urges designers, he says, “to try to find solutions that leverage both opportunities. We want people to think about these features not as separate, but as potentially integrated.”

For example, low-flow bathroom faucets can be installed in conjunction with water pressure-driven generator mechanisms hooked up as battery rechargers to power building system components like valves and solenoids. It’s actually been done, “and that’s an example of an integrated solution that saves water and energy as well,” he says.

So, how exactly does the ever-evolving LEED “design-build-certify” process work in practice these days?

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Platinum City: San Jose, CA
In mid-2005, three new buildings for a gleaming City Hall went up together—an ensemble to showcase green efficiency in an urban setting.

During the design phase of the three—an 18-story high-rise, three-story annex, and five-story-all-glass rotunda, making, all told, half-a-million-plus square feet—the City Council thought of devising its own green building standard. In this, they borrowed heavily from the USGBC. At the time, the Council’s idea and goal of localization, of what was then a national green code, made a lot of sense and still does; however, using it as a kind of blueprint ultimately caused some complication and necessitated revisions. Next Page >

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