Missing The Forest For The Trees

Early in my blogging days, I wrote a post on the problem of green sprawl--the practice of developing "green" buildings on unsustainable sites.  Can a building really be considered green if it is built on greenfields in the urban periphery (like green Wal-Marts or Best Buys), or a single family dwelling comprising of tens of thousands of square feet? Twitterer Lauren Glasscock sent along this fabulous link to the 10 dumbest "green" buildings.

I read about a new version of this phenomenon in Chattanooga.  Apparently, Unum Group is: 

[B]uilding a $20 million project that includes a parking garage to hold about 1,450 cars which will attempt to be Leadership in Energy and Environmental Design certified by the U.S. Green Building Council.

So now the big question-- Can a parking lot for 1,450 cars ever be "green"? 

To be fair, the Chattanooga Times reports:

The garage, expected to be completed in the fourth quarter of 2010, will open the way for the sale of much of Unum's 28 acres of surface parking lots.

Mr. Watjen said property will likely be turned into development for downtown, but it is unclear exactly how it will be distributed.

A garage structure is more sustainable than surface parking lots, for the runoff factor alone.  But I question the "green"-ness of erecting infrstructure for 1,450 cars.  Is this something the USGBC should be certifying? Or does it compromise the fundamental credibility of the LEED system? 

LEED 2009--A Tweak or An Overhaul?

The USGBC membership approved the new version to the LEED rating system for high performance (“green”) buildings on November 18, 2008--LEED 2009. The rollout of LEED 2009 has been many months in the making, being originally released for comment in the spring, and for second public comment in August. The documentation for LEED 2009 is voluminous, comprising several .zip files available here.  


            The basic changes are as follows:

  • Credit “Harmonization and Alignment”—In short, all of the LEED Rating Systems will have common prerequisites and credits so that there are fewer conflicting components across rating systems. The Credit Interpretation Rulings have been similarly harmonized.
  • Predictable Development Cycle—LEED will be updated on a set schedule. Next time is in 2011.
  • Credit Weighting—A “scientific” tool was used to reweight the credits in the LEED system based on a life-cycle analysis. Now, the total number of points has increased from 69 to 100. Certified requires 40 points, Silver 50, Gold 60, Platinum 80. A breakdown of each category is as follows:


LEED 2.2

LEED 2009

Sustainable Sites



Water Efficiency



Energy & Atmosphere



Materials & Resources



Indoor Environmental Quality



The following notable changes were made to specific credits:

    • SS Credit 2: Development Density & Community Connectivity
      • Credit 2 went from being worth 1 point to being worth 5 points
      • If the project is mixed use, it may be considered one of the ten basic services that are required to be located within ½ mile, as long as the service is open to the public.
    • SS Credit 4.1: Alternative Transportation: Public Transportation Access
      • Credit 4.1 went from being worth 1 point to being worth 6 points
      • Walking distance is specified
    • SS Credit 4.3: Alternative Transportation: Low Emitting & Fuel Efficient Vehicles
      • Credit 4.3 went from being worth 1 point to being worth 3 points
      • Discounted parking is available as an alternative to preferred parking for fuel efficient vehicles
      • Vehicle sharing is a new option
    • SS Credit 4.4: Alternative Transportation: Parking Capacity
      • Credit 4.4 went from being worth 1 point to being worth 2 points
      • Discounted parking is available as an alternative to preferred parking for carpool/vanpool vehicles
      • An alternative track for mixed use buildings is specified
    • WE Prerequisite 1: Water Use Reduction: 20% Reduction
      • 20% reduction in water use is now mandatory
    • WE Credit 1.1: Water Efficient Landscaping: Reduce by 50%
      • Credit 1.1 went from 1 point to 2 points
      • Groundwater seepage is added as an alternative strategy
    • WE Credit 1.2: Water Efficient Landscaping: No Potable Water Use or No Irrigation
      • Credit 1.2 went from 1 point to 2 points
    • WE Credit 2: Innovative Wastewater Technologies
      • Credit 2 went from 1 point to 2 points
    • WE Credit 3: Water Use Reduction
      • Credit 3 is now worth 2-4 points for a 30-40% reduction in water usage
    • EA Prerequisite 2: Minimum Energy Performance
      • Specifies new compliance paths, including demonstrating a 10% improvement for new buildings or a 5% improvement for existing building renovations in the proposed building performance rating  compared to the baseline building performance rating per ASHRAE/IESNA Standard 90.1-2007
    • EA Credit 1: Optimize Energy Performance
      • Credit 1 is now worth 1–19 Points (from 1-10 points in LEED 2.2)
      • 12% enhancement for new buildings is now the minimum, up from 10.5%
    • EA Credit 2: On-Site Renewable Energy
      • Credit 2 is now worth 1-7 points (from 1-3 points in LEED 2.2)
    • EA Credit 3: Enhanced Commissioning
      • Credit 3 went from 1 point to 2 points
    • EA Credit 4: Enhanced Refrigerant Management
      • Credit 4 went from 1 point to 2 points
    • EA Credit 5: Measurement & Verification
      • Credit 5 went from 1 point to 3 points
    • EA Credit 6: Green Power
      • Credit 6 went from 1 point to 2 points
    • MR Credit 1.1: Building Reuse: Maintain Existing Walls, Floors & Roof
      • Credit 1.1 went from 1 point to a range of 1-3 points for preserving 55%-95% of building components
    • EQ Prerequisite 1: Minimum IAQ Performance
      • Requirement is now ASHRAE 62.1-2007

            LEED 2009 has attempted to fix one of my major criticisms, that LEED does nothing to prevent “green sprawl”—green buildings built on unsustainable sites—first voiced here. Although there is still nothing to prevent a “green” big box store surrounded by acres of parking lot on the urban periphery from being LEED certified, the increases in points to the Sustainable Sites credits are an attempt to give more weight in the LEED system to green buildings built in mixed-use community settings linked by public transit. 



My friend and fellow Delaware Valley Green Building Council member Rob Diemer from AKF Engineering thinks that LEED 2009 changes the landscape regarding green building design.  According to him:

The affect of going to a 100 point scale with all the same credits and increasing certain credits over others definitely adds a bias toward addressing the building carbon footprint and water use.  In addition, the new reference standards are more stringent, particularly for water and energy, and therefore the impact of weighting is magnified.

We used to easily get 2 regular points and 1 ID point for reducing water use below the reference standard by more than  40% on WE Credit 3 by using low flow (not even waterless) urinals, regular 1.6 gpf toilets in the men's room, dual flush toilets in the women's room, low-flow shower heads and 0.5 gpm aerators on all the lavatory faucets.  When we analyze where the savings were being generated with the above approach we found that approximately half the savings, or a 20% reduction below the reference standard, were from the 0.5 gpm lavatory faucet aerators.  The reference standard allowed up to 2.2 gpm for these faucets so a change to 0.5 gpm was significant.  Trouble is the International Plumbing Code mandates 0.5 gpm for lavatory faucets in public rest rooms anyway so these savings were illusionary for many LEED buildings.
With the new rating system, this loop hole is closed - the International Plumbing Code is now a reference standard.  In addition, there is now a 20% water reduction prerequisite.  The strategies we have been using to get 3 points will now just barely allow us to meet the prerequisite.
On the energy side things have changed significantly as well.  The EA category was previously worth about 27% of the total base points (not counting ID).  Under LEED 2009 the EA category counts for 35%.  Coupled with Water Efficiency being increased to 10% and the increases to the transportation and urban site location credits, credits related to the building carbon footprint and water use now account for over half of the available points.  More importantly, relatively easy credits like low-VOC paint are still only worth 1 point but with a 100 point rating scale they have less importance toward any level of certification.
It will be almost impossible to get any level of certification without making meaningful attempts to reduce the building carbon footprint and water use.  I think that is significant as LEED certification at the Certified and Silver levels has become too easy.