Building Energy Modeling

NREL leads the development of physics-based modeling and simulation software tools to predict and analyze building system-level effects and performance.

Researchers look at a 3D building model in the visualization lab at NREL.

Building energy modeling researchers develop multipurpose physics-based simulation software used in the prediction and analysis of building energy use. Software engines are used to support a variety of stakeholders and use cases, including: 

  • New building and retrofit design
  • Code compliance
  • Green building certification
  • Qualification for tax and utility incentives
  • Real-time building control and operation.

Building energy modeling software is also used in large-scale analyses to inform policy decisions and help develop building energy codes. NREL is actively engaged in the areas of urban and district-scale modeling, standards, stock modeling and analysis, and building energy modeling for grid-interactive efficient buildings, among others.

Featured Building Energy Modeling Software

NREL develops, maintains, and distributes EnergyPlus™, the U.S. Department of Energy's state-of-the-art, open-source whole building energy simulation engine. EnergyPlus provides detailed and validated physics-based algorithms used by building designers and researchers to accurately model whole-building system energy performance. These models inform integrated design, early-stage and advanced R&D, standards, policy, and investment decision making.

Our team also leads the development of OpenStudio®, a cross-platform suite of powerful and flexible open-source tools to support EnergyPlus, including the Radiance engine for advanced daylighting analysis. The platform includes a software development kit, scripting and workflow automation, prototype building models and standards-related model transformation tools, and a tool supporting large-scale simulation analyses.

Project Scope

NREL's building energy modeling research is focused on:

  • Continuing to update and produce a quality EnergyPlus simulation engine and OpenStudio platform
  • Identifying and moving toward the next generation of building energy modeling simulation and analysis tools
  • Developing and integrating building energy modeling and analysis tools to support new research and innovation in building science and energy efficiency.

For more information about building energy modeling at NREL, contact David Goldwasser.