By Jared Higgins, PE, CEM, CDSM, CPMP

Energy models have become a commonly used service for several new construction and existing renovation projects. The accuracy of energy models has improved greatly over the past decade and has the potential to provide important information on utility consumption and costs on a building as designed.

So, why do the buildings sometimes not operate as predicted?

Even after one year of operation, the building performance can drop off rapidly over the next few years. Building owners that paid for the energy modeling service to help make design decisions want to see the anticipated payback. This paper will investigate several causes throughout design, construction, and facility operation that have the potential to alter the energy model results. Possible solutions to these issues will also be discussed.