LEED 2009 Launches
The third generation of the USGBC’s sustainability rating system emphasizes energy performance monitoring and begins to look at climate specific design
by Zach Mortice
Associate Editor
Summary: In the next evolution of the USGBC’s LEED™, the well-branded sustainability rating system is becoming both broader and more specific in its title credentials and has better incorporated two of the most fundamental elements of the current sustainability movement: region and climate specific design and progressive energy performance monitoring.
The AIA’s resource knowledge base can connect you to Audrey Kay Werthan’s University of Michigan report on designing energy optimized buildings. Werthan’s piece contains a step-by-step delineation of responsibilities between architects and engineers for designing energy efficient buildings.
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LEED Version 3 2009, which launches on April 27, has had its credits reweighted and its point scale revised in accordance with the prioritization of overall environmental impacts. Each credit was evaluated against 13 environmental impact categories that buildings have on the environment (examples: CO2 emissions, water quality, resource depletion, and climate change). Subject matter experts ranked these impacts in terms of their severity, and the credits that do the most to mitigate the effects of the most severe environmental impacts were weighted the highest and multiplied into a 100-point scale. LEED Standard certification requires a minimum of 40 points, Silver requires 50, Gold requires 60, and Platinum requires 80.
“You’ll be able to see more about the how each credit will be able to contribute to the big picture,” says USGBC spokesperson Ashley Katz.
The most significant change in the weighting and importance of credit categories is the energy category, which has increased to now account for approximately a third of all points. Water use points have increased from 8 percent of the total in previous versions of LEED for New Construction to 10 percent in LEED 2009 for New Construction. Points for public transit access and community density and connectivity have increased from 22 percent of the total in LEED for New Construction to 26 percent. Points dealing with materials have been deemphasized, from 20 percent of the total in LEED 2009 Version 2.2, to 14 percent in LEED 2009. Indeed, Scot Horst, a senior vice president of LEED at the USGBC, acknowledges that material choices can have a significant impact on the energy used and embodied in a building, but the amount of carbon emissions created through the fabrication, installation, and use of any material drops significantly over the life of a building relative to credits that deal with energy consumption directly. Points dealing with systems control, thermal comfort, and daylight and views have also been reduced, from 23 percent in previous versions of LEED for New Construction to 15 percent in LEED 2009 for New Construction.
Katz says that reweighting the credits was the USGBC’s attempt to fix the arbitrary assignment of points among credits, sometimes referred to as the “bike rack issue.” Earlier versions of LEED gave users a point for installing a bike rack and thus encouraging sustainable transit methods. It also gave them a point for installing energy efficient HVAC systems. Could the environmental impact of a handful of employees at an office building not driving to work really be directly equated with using more efficient HVAC systems that save money and energy on every bill the building will see for much of its life? That’s what pre-2009 LEED systems suggested, and that’s what Version 3 is looking to verify and correct. “It’s important to incentivize things that really are going to help the big picture,” Katz says.
Tracks to LEED
The new LEED system will have versions for New Construction, Existing Buildings, Schools, Core and Shell, Commercial Interiors, but not LEED for Homes. Starting June 27, all new projects will have to register with LEED 2009. In addition, the USGBC has aligned all its credits across all systems so that parallels are easy to identify and compare. Katz says LEED’s online interface has been improved as well, so that designers get a more user friendly experience and can save their project documentation process online.
The Green Building Certification Institute has both broadened the scope of people eligible for LEED accreditation and also made their credential types more subject-matter specific. They’ve developed a non-technical accreditation level called a LEED Green Associate, meant for a wide array of professionals (developers, lawyers, consultants, trade media, and marketing and public relations officials) interested in sustainability. Though its specifics are still being worked out, the new system will also include a LEED Fellow designation, available only to sustainable design leaders with deep knowledge in the field.
LEED 2009 will also include subject matter tracks for:
- LEED for Neighborhood Development, which deals with sustainable urbanism patterns
- LEED for Building Design and Construction, a general category encompassing most phases of sustainable design and construction
- LEED for Operations and Maintenance, which focuses on energy efficiency upgrades and renovations for existing buildings
- LEED for Interior Design and Construction
- LEED for Homes.
Architects and designers who are already LEED accredited professionals have three options. They can enroll in the new system by passing a special exam tailored to the specialty tracks, or they can decline to take the exam and thus be subject to a more rigorous credential maintenance program. They can also do nothing and remain LEED APs without a specialty title.
Performance matters
LEED 2009 will be the first USGBC sustainability rating system to incorporate region and climate specific credits. These credits were determined by local USGBC chapters and are tied to project locations’ ZIP codes. Each ZIP code will specify extra opportunities for four points from six credits already in the LEED 2009 system. For example, in urban Florida, credits incentivizing the use of abundant local sunshine, decreased reliance on fossil fuels, reuse of the existing building stock, and decreased reliance on insufficient wastewater plants will contain extra points. In rural Michigan, credits that incentivize the preservation of agricultural land, minimize the amount of storm water pushed into the Great Lakes, and improve the quality of this water will contain extra points.
Many sustainability experts and leaders have insisted that local climate conditions should determine every facet of green building and design—materials, form, and specific sustainability systems. With its four points out of 100 for regional specificity, LEED 2009 doesn’t call for the radical rethinking of design that many experts deem necessary.
Horst says the reasons for this have to do with the current information infrastructure of the USGBC and the assumed knowledge of designers and sustainability leaders on the total primacy of bio-regional design. Compiling region-specific sustainability credits requires local expertise in each region, and, currently, the USGBC is set up as a centralized technical committee with limited connections to a wide and diverse body of professionals who could build a more robust region-specific rating system. They have been able to reach out to such professionals though their network of local chapters, but placing more emphasis on regional design credits will take more time and effort to build and strengthen these connections. “I, sitting in Washington, D.C., can’t decide what the Los Angeles [regional] credit should be,” says Host.
And despite the current sustainability conventional wisdom, Horst says there’s a lot that just isn’t known about how climate-specific design features stack up against omnipresent concerns like carbon emissions and energy efficiency. Is diverting storm water in New York City or harvesting sunlight with photovoltaic panels in Phoenix definitively more important than simply making sure a building uses as little electricity, heating, and cooling as possible? Vernacular ideas about building tell architects that each region should evolve wildly different forms, materials, and building envelope strategies, but vernacular builders never had the mechanical flexibility and performance standards of contemporary buildings. “Is the regional issue really that big of a deal related to sustainability?” Horst asks. “I think we don’t really know.”
Regardless of the new system’s amount of region and climate-specific focus, Horst says LEED 2009 is implicitly encouraging this kind of design approach simply by holding project teams more accountable to energy performance tests. The USGBC is requiring architects and designers to monitor how their completed buildings consume energy in real time for two years. Project teams will then have to report these data back to the USGBC. By placing such a focus on day-to-day energy performance (and monitoring how their regional credits work), LEED 2009 should create a body of data that will help designers create energy efficient buildings that automatically snap into climate-specific design permutations.
“That’s where we start to get the real feedback,” says Horst. “I like that we’ve set up a structure that allows us to be thinking a lot more about performance, because that’s ultimately what really matters.” |
Sustainability at the Cutting Edge