GenSim: New open source physics-based tool for building energy demand simulation

Dear openmod community,

we are pleased to announce the release of our new simulation tool GenSim. GenSim, derived from “Generic Building Simulation”, is an open source tool based on EnergyPlus using OpenStudio. It features a wide range of presets and an Excel-based GUI, enabling efficient calculation of high-resolution energy demand profiles for buildings (heating, cooling, electricity). The GUI is currently available in German, with an English version planned for release in 2024.

GenSim allows for the modeling of buildings in both simple, generic geometry and more complex imported ones. Using an EPW-weather file, the building’s geometry, physical parameters and typical load patterns, GenSim calculates the internal loads, transmission, ventilation, shading and the heating and cooling demands as sub-hourly profiles through thermal building simulation.

The tool’s numerous presets for multiple building typologies, including different residential and commercial buildings, which are based on common guidelines and standards, facilitate the quick and easy input of parameters. This is particularly useful in the early stages of planning. However, more detailed specifications can also be used if they are known.

GenSim is available for download on GitHub. A user manual can be found here. For further details and a validation, refer to our recent publication or the openmod wiki.

GenSim was developed as part of the QuaSi project ( Other simulation tools emerging from our project will be introduced soon.

We encourage you to use GenSim in your projects and welcome any questions or discussions. You can use the forum tag “gensim” for topics specific to GenSim or the tag “quasi-software” for general questions regarding our project.

Best regards from Stuttgart, Germany
Heiner and the QuaSi-Project-Team

Just adding the cited paper: