Thanks to the recent building energy reporting ordinances passed by the City of Boston and City of Cambridge, we were able to compile the above chart, comparing the actual energy performance of Athol Public Library in Athol, Massachusetts, for which we were the MEP/FP engineer and energy modeling consultant, to the other libraries in Boston area.
Some observations and notes about the chart above:
1. The total building energy use intensity (EUI) are all based on actual energy usage. Based on this chart, the differences in actual energy performance of the recently renovated libraries are staggering. Here are some close-up comparisons for a few that have similar basis such as square footage, time of renovation and/or LEED certification:
a. Athol Public Library, 20,065 SF, 2013 renovation & new addition, LEED Platinum, EUI = 44 kBTU/SF;
b. BPL Brighton Branch, 17,208 SF, 2011 renovation, LEED Silver, EUI = 100 kBTU/SF, Athol is 2.3 times better (100/44=2.3);
c. BPL Mattapan Branch, 21,000 SF, 2009 renovation, no LEED certification, EUI = 152 kBTU/SF, Athol is 3.5 times better;
d. Cambridge Public Library, 120,186 SF, 2010 renovation & new addition, LEED Silver, EUI = 136 kBTU/SF, Athol is 3.2 times better.
2. A LEED certified library does not necessarily perform better in terms of energy than a non-certified library:
Brighton branch (LEED Silver), Honan-Allston branch (non-certified) and Hyde Park Branch (non-certified) have the same performance (EUI=100).
3. Two libraries with the same level LEED certifications could have considerably different energy performance:
Brighton Branch EUI = 100, Cambridge PL EUI = 136, they are both LEED Silver.
4. The old libraries are showing impressive EUI numbers. That, however, could be misleading. As we know, a typical old library may not have air-conditioning in the summer time; it may not even have proper ventilation to meet the code; their energy use numbers are therefore lower than a renovated contemporary library.
5. As MEP engineers, we strongly believe that the actual energy performance of a LEED-certified building has a lot to do with how the building systems are engineered and built. Athol Public Library is a great example demonstrating a highly energy efficient LEED building.
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