Modelica Library for Building Energy and Control Systems

Partial view of an implementation of a variable air volume flow system

Browse online model documentation.

February 12, 2014: Released Version 1.5 build 3
March 26, 2013: Moved development site to GitHub
June 15, 2012: IEA approved Annex 60
January 30, 2012: Released User Guide.

The Modelica Buildings library is a free open-source library with dynamic simulation models for building energy and control systems. The library contains models for

The primary use of the library is for flexible and fast modeling of building energy and control systems to accelerate innovation leading to cost-effective very low energy systems for new and existing buildings. The library is particularly suited for

All development is open-source and we welcome contributions.

The models in this library are implemented in the Modelica language, which separates the concerns between modeling (i.e., defining the model equations) and simulation (i.e., computing a numerical solution to the equations). Such a separation allows a

By using the Building Controls Virtual Test Bed, the models in this library can also be coupled to other simulation programs such as EnergyPlus, Radiance and MATLAB/Simulink, as well as to building control systems using a BACnet or analog/digital interface.

How to contribute

At this stage, contributions are particularly needed for

The development site is https://github.com/lbl-srg/modelica-buildings. If you would like to contribute, please send email to Michael Wetter.


The models are available under the following open-source license.


For help, send email at https://groups.google.com/group/modelica-buildings. This is an open group and everyone can join it. No invitation is needed.

Michael Wetter
Lawrence Berkeley National Laboratory
Simulation Research Group