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OpenStudio building energy modeling is an open-source software platform for whole-building energy simulation. The OpenStudio project describes itself as “a cross-platform collection of software tools to support whole building energy modeling using EnergyPlus and advanced daylight analysis using Radiance.” This page maps the pieces of that platform and how they relate, for researchers and building-energy modelers deciding where to start. It is not a tutorial.
Name check: other products also use the name “OpenStudio”, including a jazz-learning site and an AI creative suite. Neither is related to the energy-modeling software described here.
What OpenStudio is
OpenStudio is a collection of tools rather than a single program. According to the project’s GitHub README, the aim is to support community development and private-sector adoption of whole-building energy modeling. The simulation itself is performed by EnergyPlus; daylighting analysis is performed by Radiance. OpenStudio sits around those engines and provides the software development kit (SDK) and the applications used to work with them.
The pieces and how they relate
| Piece | What it is | Source |
|---|---|---|
| OpenStudio SDK | The software development kit, accessible from C++, Ruby, Python and C#. Its C++ documentation lists modules including airflow, energyplus, model, sdd, utilities, workflow and measure (release 3.11.0 shown). | GitHub README; SDK documentation |
| OpenStudio Application | A free and open-source application for energy modeling, supported by the OpenStudio Coalition. | OpenStudio Coalition site |
| SketchUp Plug-in | A plug-in released alongside the Application, with releases published on GitHub. | OpenStudio Coalition site |
| EnergyPlus | The whole-building energy simulation engine OpenStudio uses. It is the engine, not a competitor. | GitHub README |
| Radiance | The tool OpenStudio uses for advanced daylight analysis. | GitHub README |
Who runs it and what it covers
The OpenStudio Coalition states that OpenStudio “is developed in collaboration by NLR, ANL, LBNL, ORNL, and PNNL”, a group of U.S. national laboratories. The source code lives in the NREL/OpenStudio repository on GitHub, with folders for the core source and for Python, Ruby and C# bindings. The Coalition was founded to support the OpenStudio Application, with goals of keeping the applications free, current and functional.
Platform support: the README lists Windows, Mac and Linux. The README text does not name a license, so check the repository’s license file before reusing or redistributing code. For the general concept, see the CASRAI entry on open-source software.
Where to find downloads, code and help
- Source code and SDK: the NREL/OpenStudio repository on GitHub.
- Application and SketchUp Plug-in releases: published on GitHub, as linked from the OpenStudio Coalition site.
- API reference: the OpenStudio SDK documentation (C++), currently showing release 3.11.0.
- Questions and community help: the README points to the project website and to the community Q&A site unmethours.com.
- Python and .NET packages: OpenStudio is also listed on PyPI as “openstudio” and on NuGet as OpenStudio 3.11.0.
Strengths and limits
Strengths
- Open and multi-language: the SDK can be scripted from four languages, which suits automated and repeatable modeling workflows.
- Multi-laboratory development: five national laboratories collaborate on it, according to the Coalition.
- Free application: the Coalition’s stated purpose is keeping the Application free, current and functional.
Limits
- It does not replace the simulation engines: results depend on EnergyPlus and Radiance, so their documentation also applies.
- It is a toolkit for modelers; judging whether the inputs and results are physically sensible remains the user’s job.
- For research use, record the exact OpenStudio and EnergyPlus versions you ran. See computational reproducibility, the FAIR4RS software principles and the software citation working group for how to cite software.
Related tools
| Tool | Relationship to OpenStudio |
|---|---|
| EnergyPlus | The simulation engine that OpenStudio works with. |
| Radiance | The daylight analysis engine OpenStudio supports. |
| unmethours.com | Community Q&A site named in the README for help. |
FAQ
What is OpenStudio?
OpenStudio is a cross-platform, open-source collection of tools for whole building energy modeling using EnergyPlus and daylight analysis using Radiance (NREL/OpenStudio README, read 2026-11-07).
Who develops OpenStudio?
The OpenStudio Coalition states it is developed in collaboration by NLR, ANL, LBNL, ORNL and PNNL (openstudiocoalition.org, read 2026-11-07).
Which programming languages can use the OpenStudio SDK?
C++, Ruby, Python and C#, per the GitHub README.
Where do I download OpenStudio?
Application and SketchUp Plug-in releases are on GitHub; the SDK source is in the NREL/OpenStudio repository. Python users will also find an “openstudio” package on PyPI.
Is the OpenStudio SketchUp plugin separate from the Application?
The Coalition site lists the Application and the SketchUp Plug-in as separate releases, both on GitHub.
Is OpenStudio the same as the OpenStudio jazz or AI products?
No. Those are unrelated products that share the name.
Sources
- NREL/OpenStudio README, github.com/NREL/OpenStudio, read 2026-11-07.
- OpenStudio SDK Documentation (C++), openstudio-sdk-documentation.s3.amazonaws.com, read 2026-11-07.
- OpenStudio Coalition, openstudiocoalition.org, read 2026-11-07.
