Home Energy Score Upgrades Modeling Capabilities

The latest improvement to Home Energy Score™ enhances the tool’s modeling capabilities by incorporating a more robust software program used worldwide to model energy consumption in commercial and industrial buildings.

EnergyPlus™—a whole-building energy simulation program funded by the U.S. Department of Energy (DOE) and developed in collaboration with DOE’s national laboratories, academic institutions, and private firms—is already considered the standard by engineers, architects, and researchers for measuring energy consumption in buildings.

The switch to EnergyPlus enables Home Energy Score to produce more accurate energy estimates through comprehensive modeling calculations. Like a miles-per-gallon rating for vehicles, Home Energy Score provides consumers a way to easily compare energy efficiency across homes.  The Score relies on roughly 50 data points about a home, including its envelope (foundation, roof, walls, insulation, windows) and its heating, cooling, and hot water systems. In addition to the Score itself, recommendations for saving energy (and improving the home’s Score), are provided in a customized report. Madeline Salzman, Home Energy Score program manager at DOE, said that using EnergyPlus will provide the flexibility to add more characteristics and technologies that affect energy consumption. “As new technologies such as advanced heat pumps and low e-storm windows become more widespread, we’ll be able to incorporate them into the Score and give consumers as much information as possible about energy usage in their home,” Salzman said.

Another bonus of making the move to EnergyPlus? It will be easier to compare energy metrics between a Home Energy Score and an Energy Rating Index (ERI) (another metric used in the energy code). In addition, the National Renewable Energy Laboratory is working to integrate the Weatherization Assistant software into EnergyPlus, which will make it much easier to provide Home Energy Scores to homes in the Weatherization Assistance Program (WAP).

While the upgrade to EnergyPlus will change the calculations used to produce a Home Energy Score, there won’t be any noticeable changes to homeowners or to Home Energy Score Assessors. The only change may be, in some cases, the Score itself. Home Energy Score program staff compared 10,000 Scores using both the new and the old software.  The exercise produced an identical Score 47% of the time, and 87% of the Scores were within one point of the previous Score. For more details about EnergyPlus, visit EnergyPlus.net. Questions about the changes to Home Energy Score can be sent to [email protected].