One of the big outgrowths of the green building movement is a new focus on actual building performance. This isn’t just the individualized performance of a singular system at a point in time (“the lights come on when you flip the switch – check”), but the overall performance of the whole building over some extended period of time (annual energy consumption per square foot of building). Green buildings have touted their superior energy or resource efficiency and while there have been some success, there have also been some less than tremendous performances by allegedly high performance buildings. As a result – and in this engineer’s opinion, a logical outcome – there has been a movement towards adding a “measurement and verification” (M&V) requirement to the ratings systems. Taking the two ‘’biggest dogs in the park,” the USGBC’s LEED system and the EPA’s Energy Star program, there are two slightly differing frameworks.
LEED requires a performance target that is better than what would be predicted using “normative” energy conservation standards (i.e. ASHRAE Std. 90.1) and it requires that an energy model be developed for the project. After construction, the M&V mandate requires that the owner submit annual energy bills (for 5 years) to the USGBC and to compare the actual usage to the modeled usage. In short, it is a check to see if you are doing what you said you would do. This is valuable! It dampens the urge to succumb to “irrational optimism” when developing a model and it offers a good indication of things not running quite as planned. However, while nothing has been cast in stone that says the USGBC will yank a building certification for poor performance, it does seem reasonable to conclude that if you are going to collect actual and you are going to compare actual to modeled, then there is a strong likelihood that at some time you will need to do a reckoning between expectations and reality.
The EPA’s Energy Star system is based on a more comparative structure – Building A’s energy ‘ranking’ is based on its’ performance compared to that of similar buildings. So it is less of an “absolute” target and more of a ‘’relative” target – how is your building when compared to similar buildings (attorneys can think of it as a sort of “standard of care” for energy performance). The Portfolio Manager program is a tool which the EPA has developed so that an owner of multiple buildings can track and compare their performance as a portfolio of buildings. This type of comparison may offer insight into differences between maintenance and operating programs at comparable buildings. If you don’t know how your building is doing, you won’t be able to see ways to improve.
These M&V approaches and others are an attempt to bring the initiative benefits of green into the concrete realm of energy use and bills. This push (pull?) has occurred not only on the ‘rating agencies’ side but also from the governmental or regulatory side. As described in another article in this issue, Philadelphia is but the latest of a list of cities that has or is introducing Energy Benchmarking and Reporting legislation that requires commercial buildings to report their annual energy and water use. This type of reporting will introduce a marked change in the level of transparency in large real estate transactions in the area of energy and water use. This benchmarking will require some changes to the operating routine, but more importantly, it may reveal some areas where considerable savings can be found.
Measurement and Verification requirements, be they via the USGBC or legislative mandate, will create some documentation and monitoring challenges but are very likely to reveal some operational opportunities that will yield returns far greater than their costs. It’s not enough to just talk the talk; we now need to make sure that green buildings walk the walk.
If you are more interested in setting up an M&V program or utilizing Energy Star’s Portfolio Manager, feel free to contact MDC Systems® to help you with the process. swann@mdcsystems.com
