The Modelica Buildings Library 13.0.0, 12.1.1 and 11.1.1 were released on May 04, 2026.

The Modelica Buildings Library 13.0.0 is a major release. Version 12.1.1 and version 11.1.1 are maintenance releases, and both are backward compatible with 12.1.0 and 11.1.0, respectively.

All three versions contain various model improvements and versions 13.0.0 also includes new models.

The following major changes have been done for the Modelica Buildings Library 13.0.0

The following major changes have been done compared to release 12:

• The package Buildings.Controls.OBC.ASHRAE.G36.FanCoilUnits has been added with control sequences for fan coil units.
• The package Buildings.DHC.ETS.Combined has been replaced with improved models, and the old models have been moved to the Buildings.Obsolete package.
• The package Buildings.Templates has been refactored to use load-dependent 2D table data for chiller and heat pump models.
• The package Buildings.Fluid.AirFilters has been added with models for air filters.
• The package Buildings.Fluid.HeatExchangers.ThermalWheels has been added with models for heat recovery and enthalpy recovery wheels.
• The package Buildings.Media.Antifreeze.Functions has been added to enable calling glycol property functions without instantiating a package.
• The package Buildings.Utilities.IO.Python_3_12 has been added with models to call Python 3.12 modules from a Modelica block. This package replaces Buildings.Utilities.IO.Python_3_8 which has been moved to the Buildings.Obsolete package.
• The models of cooling towers in Buildings.Fluid.HeatExchangers.CoolingTowers have been refactored to use a data record for the performance data, and a new model of a dry cooler that uses the epsilon-NTU relation has been added.

Also, many models have been updated to improve performance, to improve compliance with the Modelica Language Standard and to correct model errors.

For a detailed list of changes, see https://simulationresearch.lbl.gov/modelica/releases/v13.0.0/help/Buildings_UsersGuide_ReleaseNotes.html

The library has been tested with Dymola 2026x, OpenModelica 1.26.3, OPTIMICA 1.66 and recent versions of Impact.

The following major changes have been done for the Modelica Buildings Library 12.1.1

Models have been updated to use Modelica 4.1.0, and to improve performance, to ensure compliance with the Modelica Language Standard and to correct model errors.

For a detailed list of changes, see https://simulationresearch.lbl.gov/modelica/releases/v12.1.1/help/Buildings_UsersGuide_ReleaseNotes.html

The library has been tested with Dymola 2025x, OpenModelica 1.26.3, OPTIMICA 1.66 and recent versions of Impact.

The following major changes have been done for the Modelica Buildings Library 11.1.1

Models have been updated to use Modelica 4.1.0, and to improve performance, to ensure compliance with the Modelica Language Standard and to correct model errors.

For a detailed list of changes, see https://simulationresearch.lbl.gov/modelica/releases/v11.1.1/help/Buildings_UsersGuide_ReleaseNotes.html

The library has been tested with Dymola 2024x Refresh 1, OpenModelica 1.26.3, OPTIMICA 1.66 and recent versions of Impact.

More information and download

For more information and download of the Modelica Buildings Library, visit https://simulationresearch.lbl.gov/modelica/.