Autodesk and U.S. Department of Energy Team on Open Sourcing Major Update to EnergyPlus Engine

Categories: Architecture Autodesk Foundation

At Greenbuild 2013, Autodesk Spotlights New Initiatives and Technologies for Sustainable Building Community


In a public handoff to the U.S. Department of Energy (DoE) at Greenbuild 2013 in Philadelphia today, Autodesk is donating completely re-written EnergyPlus engine source-code, to be made available under the DoE’s open source license.

As a long-time contributor to the sustainable building design community and proponent of the democratization of building performance analysis tools, this initiative is just one of several Autodesk is spotlighting at the annual conference.  The company is also unveiling new Building Performance Analysis (BPA) Certificate and Credits programs. In the LEED realm, a Revit plug-in for reducing LEED daylighting analyses from weeks to hours is being released on Autodesk Labs.  In addition, Autodesk parted the curtains on two emerging technologies offered to a few select pilot customers — a LEED Automation tool and a Revit Credit Manager for LEED®. Finally, Autodesk also announced an expanded Energy Analysis capability, which is now available for Revit 2014 through Autodesk Subscription.

Updating EnergyPlus

The Department of Energy’s EnergyPlus software is a crucial energy analysis engine for the sustainable building community.  However, EnergyPlus has not achieved maximum adoption by either design practitioners or design and analysis software vendors like Autodesk.


One aspect of the problem has been the EnergyPlus code itself—not the calculations, but the language they are written in. As a physics engine, EnergyPlus was initially written in FORTRAN, a language aimed at scientific programs to be run by a select few for days and weeks on supercomputers. But nowadays, EnergyPlus needs to be run by many more architects, engineers, and energy consultants on multi-core, graphics-enabled desktops and in the cloud. It also needs to work with modern Building Information Modeling (BIM) design applications, auditing tools, and energy dashboards.

To address this limitation, Autodesk took the initiative to translate EnergyPlus—more than 600,000 lines of code—to C++, a modern object-oriented language that is better supported on mass-market hardware and software platforms. Autodesk is donating this new version of EnergyPlus to DoE under the terms of EnergyPlus’ current open-source license. Autodesk will also continue to work with DoE on improving the common EnergyPlus codebase, focusing on improving its speed and BIM support.

In 2011, Autodesk donated source code modifications that increased EnergyPlus’ execution speed, as reported here by the DoE.

New BPA Professional Certificate and Credits

The Autodesk Building Performance Analysis (BPA) Certificate program, launched in August for students and educators worldwide, is now open to professionals seeking continuing education credit. The expansion of the program to professionals aims to remove barriers to learning the skills necessary for an industry-wide transition to performance-based sustainable design. The free, self-paced online course teaches building science fundamentals and Autodesk building performance analysis software tools, including Revit, Vasari, and Green Building Studio.

New today are Autodesk BPA Credits, which are a spin off of the certificate program, specifically for the continuing education of professionals. Three free, online self-paced courses are now open and professionals are eligible to sign up to earn USGBC and AIA credits.  The pilot courses cover: Energy Literacy & Building Loads; Whole Building Energy Analysis; and Daylight Analysis.


Previews of New LEED Tools

Also at Greenbuild, Autodesk signaled its support for professionals working on LEED projects with early access and previews to new technology solutions:

  • Super-fast Daylighting Analysis for LEED®Now available on Autodesk Labs, the new Daylighting Plug-in for Revit analyzes the entire model using Autodesk’s 360 Rendering cloud service in a matter of minutes. This Daylighting analysis tool streamlines LEED EQc8.1 calculations and credit documentation within Revit, and it can reduce time required for a daylighting analysis and documentation workflow from a couple of weeks to under a few hours.  The cloud-based Autodesk 360 Rendering service also provides advanced daylight and artificial lighting simulation capabilities directly from detailed Revit models.


  • LEED Project Automation – Autodesk demonstrated its Project Automation App for LEED® certification that has direct access to LEED Online through USGBC’s LEED Automation Partner Program. The app based on Autodesk PLM 360 aims to drastically simplify LEED® documentation and project management. It helps a LEED team monitor tasks, teams, milestones, documents and action items, while providing insightful and actionable reports, charts and dashboards. The app will be offered to a few select pilot customers through the Autodesk Feedback Community. Please contact if you are interested in piloting this promising technology.


  • Revit Credit Manager for LEED®: Autodesk also demonstrated a Revit Credit Manager for LEED®. This Revit add-in aims to automate LEED calculations and improve design decisions for a number of LEED credits, right from within the design environment. With real-time feedback earlier in the project, it will make LEED submittals faster and more reliable. The emerging technology will be offered to a few pilot customers through the Autodesk Feedback Community.


Autodesk has invested in dramatically streamlining whole building energy analysis in Autodesk Revit 2014, which represents a major step towards easier, faster BIM-based building performance analysis.This new feature, ‘Energy Analysis for Autodesk Revit 2014,’ is available with Autodesk Subscription and is powered by the cloud-based service Autodesk Green Building Studio (GBS).  By eliminating the need to rebuild the Revit model or build an entirely separate model specifically for energy analysis, the new capability provides major savings in both the time and skill required to conduct Energy Analysis and is especially valuable at the early stages of the design process when Energy Analysis can have the greatest impact.


All of the initiatives and technologies described above build upon numerous other Autodesk efforts at democratizing software for energy efficient buildings in 2013, including a Potential Energy Savings tool introduced in May and Tally, a new software application from KieranTimberlake (for which Autodesk supported development and testing) that allows designers to measure the environmental impact of building materials directly in a Revit model. Greenbuild attendees can learn more and see demos of all the technologies discussed at the Autodesk booth at Greenbuild (#2237).