Driving client value and cost savings through energy modeling
Find out how energy modeling can be used to find the most cost-effective options for the design of both passive and active systems
A key part of AIA's 2030 Commitment is encouraging the incorporation of energy modeling to inform design and decision-making on every project, especially during the early design phase. While energy modeling does not guarantee energy use reduction, it’s an important tool that—used early and iteratively—can lead to returns on investment in remarkably short timeframes.
Energy modeling can be used to find the most cost-effective options for the design of both passive and active systems, making tradeoffs to achieve both immediate and long-term cost savings. Particularly for larger buildings, energy modeling fees tend to be dwarfed by uncovered reductions in construction cost and energy cost. And for smaller buildings, energy modeling can include more targeted investigations that can help inform design—such as windows and shading, insulation and mechanical systems—that will continually pay off through the life of the building.
Unfortunately, many project teams only use energy modeling late in the design process—design development or construction documents phases—for code compliance or to document energy points for green certifications. Though better than having no modeling options to compare for cost and effectiveness, late modeling leaves teams with a drastically smaller range of energy-efficiency options that are much more expensive to implement. And while modeling does not cause energy use reduction, its use does help architects make better decisions to reach their targets. In 2016, 2030 Commitment projects that were modeled averaged predicted energy use intensity (pEUI) reductions of just over 50 percent, compared to only a 35 percent pEUI reduction for projects that were not modeled.
“The 2030 Commitment spurred a lot of firms, including ours, to get serious about tracking energy performance.” - Kjell Anderson, AIA, sustainability coordinator at LMN Architects
Despite the benefits of energy modeling, it’s not used as a design tool as often as it needs to be, whether because of the time commitment, perceptions of cost, or other barriers. In fact, the percentage of modeled projects in the 2030 Commitment fell from 2015 to 2016. But for those firms that are incorporating it—such as Seattle-based LMN Architects—energy modeling has become an increasingly important piece of their process, because of both the environmental impact of energy use reductions and the significant potential economic return on investment for energy modeling.
“The 2030 Commitment spurred a lot of firms, including ours, to get serious about tracking energy performance,” says Kjell Anderson, AIA, sustainability coordinator at LMN. “You can’t even discuss goals without a baseline to compare against, and external baselines are hard to come by for the special project types that we work on, such as convention centers and performing arts.”
For LMN, the Commitment also forced a re-examination of where they stood on energy savings. “We considered ourselves a high-performing firm, but we were only looking at our best projects, not our average projects,” Andereson explains. “2030 reinvigorated our conversation around setting goals and achieving them on all projects.”
How the University of Iowa used energy modeling
This dedication to setting and achieving goals with the help of energy modeling was on display during the design of the University of Iowa’s Voxman School of Music building, which opened in a new location in 2016 after the previous building was destroyed by floods in 2008. One of the earliest pieces of the project—before the start of schematic design—was to meet with the utility, MidAmerican Energy, to begin its energy incentive program for new construction projects. To meet the incentive program, in which the utility provides energy modeling services along with cash incentives for equipment, the owner and project team set a goal of achieving an energy savings at least 40 percent beyond the baseline.
Working with associate architect Neumann Monson, mechanical and electrical engineers Design Engineers, and energy modeling consultants The Weidt Group, LMN incorporated daylight modeling, HVAC analysis, and energy massing analysis into the design process for the 184,000-square-foot building. The project also had to balance energy savings with the need for acoustically-driven design of a 700-seat concert hall and other recital, rehearsal, and classroom spaces, along with specific temperature and humidity requirements to protect sensitive instruments. The modeling showed that a high-performance envelope (R-24 plus thermal mass) would produce significant energy savings and reduce mechanical equipment size. Other savings came from a unique mechanical design that captured waste heat from the chilled water loop circulating around campus, an option that wouldn’t have been selected without the use of energy modeling.
“Early energy modeling enabled us to consider some out-of-the-box ideas that would not have be feasible to incorporate later in the process,” says Dwight Schumm of Design Engineers. “The heat recovery chiller system is the perfect example of this.”
At final analysis, the mechanical and design adjustments realized through modeling led to an impressive reduction of nearly 70 percent when compared to a code-compliant baseline, greatly exceeding the project’s minimum threshold of a 40 percent reduction. In a simplified analysis of payback, the increased construction cost for energy savings measures came out to approximately $550,000 after incentives from the utility company were factored in. With an annual energy cost savings projected at about $425,000, that meant the payback period for additional construction cost came out to just 1.3 years for the university.
For firms looking to incorporate energy modeling in a way that maximizes return on investment, Anderson recommends looking at the Database of State Incentives for Renewables and Efficiency (DSIRE) or to contact the utility company directly for information on their programs. “Without energy modeling, we would not have gotten the financial incentives, and we probably wouldn’t have considered some of the more innovative solutions that were ultimately used,” Anderson says. “The modeling helps to prove energy savings and guide decisions.”
Melissa Smith Nilles is an account director at Fifth Estate, a communications firm in Washington, DC.