OpenStudio
Pricing. OpenStudio is free and open source. See full pricing · Updated October 14, 2026
OpenStudio is a free, open-source energy modeling toolkit for Windows, Mac, and Linux that drives EnergyPlus and Radiance through a graphical app, a command line, and Ruby or Python measures.
Whole-building energy models still end up in EnergyPlus, and many teams do not want to hand-edit that input file. OpenStudio puts a versioned API in front of the engine, with space types that are easier to assemble than raw objects, plus bindings for Ruby, Python, C#, and C++. Radiance sits beside EnergyPlus when the question is daylight.
The OpenStudio Application is the graphical place for envelope, loads, schedules, and HVAC, and ResultsViewer plots time-series output. A SketchUp plug-in builds the geometry, and gbXML or IFC can be imported for that geometry as well. The OpenStudio Coalition maintains those graphical apps, while the SDK and command line run the same workflows on Windows, Mac, and Linux.
Measures are scripts that change a model or write a report. Ruby is the original language, and Python has had a first phase of support since version 3.5.0. Hundreds of them sit on the Building Component Library, which the project has moved to bcl.nlr.gov. OpenStudio Standards uses that same measure system to build prototype buildings and to run the ASHRAE 90.1 Appendix G performance rating method used for code, LEED, and utility incentives.
SDK 3.11.0, posted on 15 January 2026, is paired with EnergyPlus 25.2.0, Radiance 5.0.a.12, and Ruby 3.2.2 on the project's compatibility matrix. Daylight work goes through Radiance. Larger studies, including calibration and stock-level measure runs, can be queued through OpenStudio Server. The SDK license allows redistribution if the copyright notice stays, and a modified copy may not use the OpenStudio name.
Specifications
Pricing
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Pros and cons
Pros
- Free to download, with a license that allows redistribution when the notice is kept
- Windows, Mac, and Linux, including a command line
- EnergyPlus 25.2.0 and Radiance are pinned to a published SDK version
Cons
- A modified redistribution cannot use the OpenStudio name
- The compatibility matrix says See for the SketchUp version on SDK 3.11.0, so the plug-in year is not listed there
- The Building Component Library has left its old domain for bcl.nlr.gov
Key features
EnergyPlus through an API: SDK 3.11.0 ships with EnergyPlus 25.2.0, plus a command line for Windows, Mac, and Linux.
Graphical modeling: The Application edits envelope, loads, schedules, and HVAC. ResultsViewer plots output.
Geometry: SketchUp plug-in, plus gbXML and IFC import.
Measures: Ruby scripts, with phase-one Python support since version 3.5.0, shared on the Building Component Library.
OpenStudio Standards: Prototype buildings and ASHRAE 90.1 Appendix G transformations.
Radiance daylight: The 3.11.0 matrix lists Radiance 5.0.a.12.
OpenStudio Server: Queue large measure studies such as calibration, optimization, and stock analysis.
Pricing
Open source
Free
No purchase price on the vendor site. The SDK license allows source and binary redistribution if the copyright notice and conditions stay with the copy. A modified version may not be called OpenStudio.
Prices come from each vendor’s public listings and can change. Double-check the current price on the vendor site before you buy.
Frequently asked questions
Is OpenStudio free?
Yes. OpenStudio is an open-source download with no price on the project site. The SDK license allows you to redistribute source or binaries if you keep the copyright notice and the license conditions. A modified copy may not use the OpenStudio name without written consent, and the copyright line is Alliance for Energy Innovation, LLC, 2008 through 2026.
Does OpenStudio run on Mac and Linux?
Yes. The project describes OpenStudio as cross-platform on Windows, Mac, and Linux, and the command line is documented for those same systems. The graphical Application and the SketchUp plug-in are part of that collection. The SDK 3.11.0 compatibility matrix does not name a SketchUp year; it says See and points plug-in details at a legacy repository.
What files can OpenStudio import, and which EnergyPlus version is current?
The homepage says geometry can be imported from gbXML and IFC, and geometry can also be built in the SketchUp plug-in. SDK 3.11.0, released on 15 January 2026, is listed with EnergyPlus 25.2.0 and Radiance 5.0.a.12. Daylight analysis uses Radiance. The matrix is the place to check an older SDK, because the EnergyPlus version changes with each release.
Can OpenStudio run an ASHRAE 90.1 Appendix G model?
Yes. OpenStudio Standards is a set of measures and resources that build prototype models, such as an office, hospital, or primary school, and apply the ASHRAE 90.1 Appendix G performance rating method. The project lists that path for code compliance, LEED, and utility incentive calculations. The measures themselves can be Ruby, or Python under the phase-one support added in version 3.5.0.
How is OpenStudio different from editing an EnergyPlus file by hand?
EnergyPlus is still the simulation engine. OpenStudio adds a stable API, space-type abstractions, a graphical application for envelope, loads, schedules, and HVAC, and measures that change the model without rewriting every object. The command line and OpenStudio Server then repeat those measures across many runs. It is not a separate physics engine.
Who maintains OpenStudio, and where did the measure library go?
The OpenStudio Coalition maintains the SketchUp plug-in and the OpenStudio Application. The SDK is published in the NatLabRockies OpenStudio repository, and the license holder named in that repo is Alliance for Energy Innovation, LLC. The Building Component Library, where measures and related content are posted, has moved to bcl.nlr.gov. The site said the old domain would be retired at the end of May 2026.
Tutorials and learning
Sources
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