Although the results of the study were positive overall (i.e., LEED Certified buildings are saving energy), the study also highlights some areas for concern. From our perspective as professional energy analysts, one the more troubling findings was the large discrepancies between a building's predicted energy use and its actual energy use. In fact, over half of the energy models in the study were found to have troubling inaccuracies (i.e., deviations between expected energy use and actual energy use of greater than 25%), and a full 12% of the LEED Certified buildings studied performed worse than would be expected for a traditional, built-to-code building.
While some of the deviations found in the study may be due to differences between design and operating procedures, we suspect that energy modeling practices contributed significantly to the poor outcome.
Modern day energy modeling is complex and unforgiving in nature. To do it well requires a thorough understanding of both engineering principles (e.g., heat transfer, moisture transport, and materials physics) and software limitations.
In all but the simplest of simulations, rather significant engineering assumptions have to be made, and proper training and experience are required to ensure that the software’s results are interpreted correctly. Without a comprehensive understanding and review of an energy analysis, a design team risks basing its decisions on uncertain results (unfortunately, problematic results are common with today’s energy modeling software - especially when modeling complex systems such as those used in LEED-Certified buildings).
Modern day energy modeling is complex and unforgiving in nature. To do it well requires a thorough understanding of both engineering principles (e.g., heat transfer, moisture transport, and materials physics) and software limitations.
In all but the simplest of simulations, rather significant engineering assumptions have to be made, and proper training and experience are required to ensure that the software’s results are interpreted correctly. Without a comprehensive understanding and review of an energy analysis, a design team risks basing its decisions on uncertain results (unfortunately, problematic results are common with today’s energy modeling software - especially when modeling complex systems such as those used in LEED-Certified buildings).
Consequently, at Building Synergies, all of our energy analysts are licensed, professional engineers.
