A prospective client asks: Is it possible for our building to get LEED-EB certified? Although we'd love to get the rating, we're not sure if we'll meet the minimum energy efficiency standard to make the effort worthwhile. How do we find out before we get too far down the road?
KELLY: That's a great question, and you're not alone in wondering about this, because in truth it can be a little complicated.
But first, for our readers who aren’t familiar with LEED for Existing Buildings (LEED-EB), or the Energy Star Portfolio Manager (ESPM), which is the benchmarking tool required by LEED-EB, here is a quick overview:
The LEED-EB rating system recognizes buildings for their ongoing high performance in sustainable operations and maintenance. This rating system relies on another tool, Energy Star Portfolio Manager (ESPM), which was developed by the Environmental Protection Agency (EPA). It’s currently the best available national benchmark for building energy performance. It is built on a baseline of data collected from the Commercial Buildings Energy Consumption Survey (CBECS) which includes a wide variety of buildings, from old to new, and leaky to tight.
One of the key prerequisites of LEED-EB is proving that your building’s energy performance is, to paraphrase, “better than average”. You can use ESPM to compare your building’s energy use with similar buildings. This tool assigns a score (a rating on a scale of 1 to 100). A score of 69 or higher means the building has met one of the eligibility requirements for LEED-EB certification. Simple, right?
The reason it gets confusing is that not all buildings are eligible for a score from ESPM. The basic eligibility requirements are clearly stated on the ESPM web site.
However, there are sometimes complications. For example, some space types have their own additional set of requirements. And sometimes, when combined, the requirements don’t quite work for buildings that otherwise seem eligible. For example, two basic requirements are
1. meeting the minimum square footage (usually 5000 sq ft)
2. having building space types for which there is data to compare to
But if you have a building that is 10,000 square feet, half hotel (5000 sq ft) and half office (5000 sq ft), you won’t be eligible for a score because neither portion takes up more than 50% of the total square footage.
The good news is, even if you’re not eligible for a score on a scale of 1 to 100, you should still be able to use ESPM to get certified under LEED-EB. The LEED rating system has a calculator that allows you to plug in data points generated by ESPM, specifically your “weather-normalized source energy intensity”. Plugging this number into the calculator allows you to determine whether you are “better than average” or not.
There are other options for complying, too. You can do your own detailed analysis of your historical energy use (normalizing the baseline for occupancy changes and weather), or you can do that plus collect data from other comparable facilities. This can take a lot of time and, because these methods are not as reliable, you may find that there are fewer points available.
My best advice is to just give ESPM a try—especially since, starting in 2011, it’ll be required reporting in Washington State for buildings larger than fifty thousand square feet. Enter your space types, energy use, occupancy and other data as accurately as you can. If you don’t see a rating in the upper right, click on the “NA” and you’ll get a custom message that explains why. If the answer is that you are not eligible for a rating, then get your “weather-normalized source energy intensity” from ESPM and use the LEED-EB calculator to get your adjusted benchmark.
Kelly Kirkland, LEED AP O+M and CSBA is a Project Associate at O'Brien & Company and provides technical assistance to the firm’s clients seeking LEED-EB: O&M certification. The firm also provides a LEED-EB: O&M "Lite Bite" to help you get up you get up to speed on the ways you can use this standard to your advantage
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