LEED-NC No Guarantee of Data Center Operating Efficiency

I've reported on data centers that have been built to LEED standards. The more I learn about LEED in practice, the more I am convinced that organizations need to carefully weigh the costs/benefits of LEED for New Construction (LEED-NC) as a Green ICT tactic. Key to the issue is that LEED 3.0 NC (LEED 2009) neither requires Energy Measurement and Verification (M&V) nor requires sustained achievement of energy benchmarks after a building is commissioned.

Alec Appelbaum in the New York Times reports that while LEED-NC ratings have become "great marketing tools", LEED compliance in no guarantee of low energy consumption or low CO2 emissions.

But while the standard is well-intentioned, it is also greatly misunderstood. Put simply, a building’s LEED rating is more like a snapshot taken at its opening, not a promise of performance…market-driven motives wouldn’t matter — if LEED in fact measured energy performance. But it can’t: some certified buildings end up using much more energy than the evaluators predicted…a five-year-old building can turn into an energy hog and still carry its LEED designation

There are many ways to get a building LEED rated; energy efficiency may or may not be a priority in any given project. Most important, Operators of LEED-NC buildings do not have to invest in post-construction programs to monitor resource consumptions and toxin emissions. Nor do they have to invest in initiatives to insure that building managers, tenants, and users understand, adopt, and maintain green operating practices for sustained performance. This is despite the availability of software and other tools to do this.

As a result, the National Research Council Canada – Institute for Research in Construction found in an analysis of 100 LEED certified commercial and institutional buildings:

On average, LEED buildings used 18-39% less energy per floor area than their conventional counterparts. However, 28-35% of LEED buildings used more energy than their conventional counterparts. Further, the measured energy performance of LEED buildings had little correlation with certification level of the building, or the number of energy credits achieved by the building at design time.

Green ICT should1 be all about quantitative performance through evidence-based sustainability. Enterprises and institutions wishing to use LEED-NC to make a one-time purchase of green virtue ("trophy buildings") without ongoing sustainability investments most easily can do so with a non-ICT facility. And while LEED-NC should be considered for any new building, most ICT facilities can make significant energy/emissions improvements without a new building.

Organizations traveling the LEED-NC path have several options for increasing the likelihood of energy-efficient operation. One is to make sure that as many of the LEED construction points as possible are for energy efficiency. Bamboo floors and bike racks are fine, but they're no substitute for energy features. Another option is LEED for Existing Buildings: Operations & Maintenance (LEED-EBOM). LEED administrator USGBC offers free LEED-EB registration for LEED-NC projects.

A post-construction option outside of LEED is EPA ENERGY STAR for buildings, which includes features specifically for data center buildings and spaces.

Update 2010.06.08
More data comes from a study by the New Buildings Institute (NBI) and funded by LEED-owner USGBC, which took a look at the "link between intention and outcome for LEED projects." It notes that while the majority of the "medium energy use buildings" buildings studied had above-average energy performance, "one quarter of these buildings had [ENERGY STAR] ratings below 50, meaning they used more energy than average for comparable existing building stock." Again, LEED-NC design is no guarantee of energy-efficient operation, even for normal office buildings.

The results become even more problematic with “high energy use buildings [that] primarily include data center and lab uses."

alignment between predicted and actual energy use for the high energy buildings is very poor, even on average. In fact, on average these buildings use nearly two-and-a-half times as much energy as was predicted during the design phase [emphasis mine]…This discrepancy suggests the actual performance characteristics of these building types are not well understood by the design community. This has significant implications on any life-cycle cost analysis that might have formed the basis of design decisions on cost-effective systems, operating budget predictions, system sizing, load planning and a host of other issues. It is clear there is a need for significant additional research into the performance characteristics for these building types and for direct feedback to the design and owner community. The data also suggests LEED may need to re-evaluate how these project types are treated with respect to energy performance achievement.

While LEED-NC certification has a number of positive attributes, is not a guarantee of energy-efficient operation. In particular, LEED-NC certification for ICT facilities like data centers, which tend to be very much about sustained energy-efficient operations, needs to be carefully weighed against other investments.

Update 2011.01.17
LEED NC is undergoing revision; the new standard is scheduled for 2012. (Read a guide to the proposed LEED 2012 draft.) The current draft incorporates an energy Measurement and Verification (M&V) option, but does not make final certification conditional on actual performance compared to a benchmark set (as does ENERGY STAR for Data Centers). Nor does there appear to be any improvements targeted to the challenges of those "high energy use buildings" described above. The draft does address M&V of water as well as energy. Data centers can be major water consumers. The bottom line is that I found little in the proposed draft to change this post's assessment of LEED NC as applied to ICT facilities.


1 Green ICT should be all about operational performance, but this is not always true. For example, EPA data suggests that air-side economizers are not properly operated in data centers. This is another example of the potential variance between design features and how they are actually utilized.