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Lead Performers:
-- National Renewable Energy Lab (NREL) – Golden, CO
-- Argonne National Lab (ANL) – Argonne, IL
-- Lawrence Berkeley National Lab (LBNL) – Berkeley, CA
-- Oak Ridge National Lab (ORNL) – Oak Ridge, TN
-- Pacific Northwest National Lab (PNNL) – Richland, WA
-- GARD Analytics – Oak Park, IL
-- Empty Crate Software – Denver, CO
-- Energy Trust of Oregon – Portland, OR
-- Austin Energy – Austin, TX
-- CPS Energy – San Antonio, TX
-- Big Ladder Software – Denver, CO
-- Concept3D – Denver, CO
-- Performance Systems Development Consulting – Ithaca, NY
-- Xcel Energy – Denver, CO
-- National Grid – New York, NY
-- California Energy Commission – Sacramento, CA
-- Architectural Energy Corporation – San Francisco, CA
-- Bonneville Power Administration – Portland, OR
-- Penn State University – State College, PA
-- Wrightsoft – Lexington, MA
-- Carmelsoft – San Rafael, CA
-- Group14 Engineering – Denver, CO
-- Natural Resources Canada – Ottawa, ON Canada
DOE Funding: $1,550,000 in FY16, $6,250,000 to date
Cost Share: $4,700,000 to date
Project Term: Indefinite
Project Website:
Funding Opportunity: Commercial Buildings Integration core funding

Project Objective

OpenStudio is DOE’s open-source “operating system” for building energy modeling. Started in 2008 with an EnergyPlus geometry creation plug-in for the 3D drawing tool SketchUp, OpenStudio has grown into a robust, full-featured software development kit (SDK) that automates many of the functions associated with creating energy models, modifying existing energy models to create design alternatives, running energy simulations, and collating, analyzing, and visualizing results from energy modeling experiments. OpenStudio automation dramatically reduces the effort required to build applications that use energy simulation and is aimed at growing and supporting the ecosystem of end-user simulation tools. By providing common infrastructure, OpenStudio allows third parties to focus on adding their individual differentiating value and on serving their clients. OpenStudio allows DOE to realize its energy modeling market vision of “serving 50 energy modeling application vendors, not 50,000 energy modeling application end users.” DOE is consolidating its energy modeling application portfolio around OpenStudio.

The distinctive technical feature of OpenStudio is the concept of “measures,” small interpreted programs that can transform a model, or query a model, or query a model and its results. Measures—named so because many of them correspond to energy-conservation measures—can perform transformations that are as simple as changing insulation levels or as complex as reconfiguring fenestration, shading, and controls to optimize for daylight harvesting. Measures are lightweight, easy to create and modify, and provide a way to customize OpenStudio and its capabilities without having to modify the core SDK. Beyond enabling parametric analysis—the systematic application of measures to a model in various combinations—measures dramatically reduce the effort required to construct energy models, while improving their consistency and quality. Over 125 measures are already available on the Building Component Library (BCL), an online repository of OpenStudio content. Nearly 100 more are in development.

In addition to measures, the OpenStudio SDK implements a number of common services. It provides translation from exchange standards like gbXML and to the individual input formats of different engines like EnergyPlus, CONTAM, ESP-r, and the CEN/ISO 13790 Standard for fast, algebraic monthly and hourly energy calculations. OpenStudio also generates inputs for the lighting engine Radiance, unifying energy and lighting analysis in a single model. It encapsulates run management on personal machines, local clusters, or the cloud. And it includes common functions like uncertainty analysis, optimization, and model input calibration.  OpenStudio is packaged with a number of example applications—the SketchUp plug-in, a simple graphical editor for non-geometry model inputs like zoning, schedules, and HVAC systems, a results viewer, and a parametric analysis tool—that demonstrate the capabilities of the SDK and are usable in their own right.

Project Impact

Despite existing in its current form since 2010, OpenStudio has already had significant uptake and impact. The project has more than 20,000 registered users. More importantly, several significant and diverse applications have already been developed on it. Concept3D Inc.’s simuwatt Energy Auditor is a tablet-based application for performing investment-grade commercial building audits.  In pilots, simuwatt was shown to significantly reduce audit effort, while providing more consistent, higher quality outcomes. The California Energy Commission’s CBECC-Com is a performance-path code compliance tool for California’s Title24—BTO is extending CBECC-Com to enable compliance with ASHRAE 90.1. EDAPT is an Energy Design Assistance Program Administration website developed by Xcel Energy of Colorado. In its first year, EDAPT has saved Xcel over $500,000, while increasing the number of energy consultants and new construction starts in the Xcel’s commercial new construction incentive program. BTO is working with Xcel to share EDAPT with other utilities. COFEE is a portfolio-scale energy-efficiency incentive customization tool developed in collaboration with National Grid. OpenStudio forms the computational basis of DOE’s Commercial Asset Score asset-rating tool and will soon be used in BTO strategic analysis. The first commercial early-stage architectural design application using OpenStudio will be released early in 2015.

The OpenStudio project also led the way for other BTO software development efforts in its use of open-source licensing and agile development processes and tools. 

Recent Publications and Presentations

Technical Support

For technical support questions, please search the public Q&A site for an existing answer to your question. If one is not found, please post your question to the site being sure to include 'openstudio' as one of the tags. Both the OpenStudio development team and the larger OpenStudio user community monitors this site.


DOE Technology Manager: Amir Roth
Lead Performer: Larry Brackney, National Renewable Energy Laboratory

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