tallyCAT Climate Action Tool

tallyCAT Climate Action Tool

Win64, English

C Change Labs
tallyCAT™ is a free Revit plugin integrated with EC3, the world's leading tool for construction sustainability. Export quantities, visualize impacts, and build a library of sustainable assemblies.

General Usage Instructions

tallyCAT can be used from schematic design through to as-built digital twins. For best results, use an Autodesk® Revit® model with quantities and materials fairly well detailed, at least for the most massive components (foundation, core, shell) and with the materials labeled.  

Create a free EC3 account at https://buildingtransparency.org/auth/register.    

  • For the most integrated experience, register with your Autodesk account.
  • If you are working with an organization that has its own Enterprise instance of EC3, register at that URL instead.

Export material quantities from Revit into EC3

Identify each material (concrete, steel, gypsum…)

  • tallyCAT starts you with a reasonable guess
  • Users should refine each material search

Evaluate climate impact based on product-specific 3rd party verified EPDs.

Visualize hot spots and the biggest carbon reduction opportunities

Generate graphs and reports

Synchronize between Revit and the EC3 model in the web

Annotate your Revit model & components so you can reuse your work

Save libraries of materials and assemblies for future use




To install, download and open the MSI. 

  • You will need administrator access to install it.
  • By default, tallyCAT installs for Revit versions 2020 through 2024. You can restrict it to only a few versions during installation.  
  • tallyCAT will automatically check for updates and prompt you when a new update is available.


To uninstall, use the Windows add/remove programs feature.  

Default install locations:

  • Addin data in "ProgramData\Autodesk\ApplicationPlugins\tallyCAT.bundle"
  • Binaries in "Program Files\C-Change Labs Inc\tallyCAT"
  • User files in "Users\[USERNAME]\AppData\Local\C-Change Labs Inc\tallyCAT"


This means that it places tallyCAT addin data to "ProgramData\Autodesk\ApplicationPlugins\tallyCAT.bundle"

and the plugin binaries to "C:\Program Files\C-Change Labs Inc\tallyCAT"

Also, the plugin should be available for every user on that machine. The user data goes to "C:\Users\[USERNAME]\AppData\Local\C-Change Labs Inc\tallyCAT"

Additional Information

tallyCAT is a free sustainability plugin by BuildingTransparency.org, a Washington State environmental charity.

  • Software development by c-change-labs.com
  • Developed in partnership with Perkins+Will.
  • tallyCAT Library Browser original design courtesy of the Design Technology Team at ZGF Architects
  • tally® original design courtesy of KT Innovations
  • We gratefully acknowledge the financial support of the Province of British Columbia through the Ministry of Energy, Mines and Low Carbon Innovation.

Known Issues


Company Name: C Change Labs
Support Contact: support@c-change-labs.com

Author/Company Information

C Change Labs

Support Information

Support is available via the Help menu in the plugin, and via the Report Bugs and Feedback button inside EC3. 

Version History

Version Number Version Description


Version 1.3.0 adds support for additional Enterprise instances of EC3, via dropdown or a custom URL.

General Availability with 2024 support, search/update library elements that have changed, assembly GWPs that scale with when you change shape, and many more features. Added F1 support and fixes for some Revit 2022 users who had DLL conflicts.


General Availability with 2024 support, search/update library elements that have changed, assembly GWPs that scale with when you change shape, and many more features.
Go top