> For the complete documentation index, see [llms.txt](https://docs.cscale.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs.

# Tally User's Guide

> 🚧 **BETA.** Tally 2.0 is in beta. It is not a finished product, and is not appropriate for reporting or compliance of any kind.

Tally 2.0 is a Revit plug-in that runs a whole building life cycle assessment (wbLCA) on your model as you design it. It reports more than whole life carbon: six impact categories plus mass, across the full life cycle of the building. You associate the materials in your Revit model with LCA data, tell Tally how to translate model geometry into the quantities an assessment needs, and get results that update as the model changes, without leaving Revit.

Tally 2.0 connects to C.Scale, so takeoffs from a Revit model can be pushed into a C.Scale project as a scenario and worked on by people who don't use Revit. Connecting is not required, but we recommend it on every project.

### About the beta

The beta is not a finished product. It will be incomplete, it will occasionally crash, and it may return incorrect results. Treat this version as a sandbox, not a production tool; models you build during the beta may not carry forward into later releases. The beta is not appropriate for reporting or compliance of any kind. We will collect detailed usage data about your use of Tally during the beta phase, beyond the current bounds of the terms of use. Do not add any private or confidential data to the beta release.

### Who can use Tally 2.0

Tally 2.0 is available to every organization on a paid C.Scale plan. You sign in with your existing C.Scale credentials. There's no separate Tally account, license key or serial number.

If your organization isn't on a paid plan and you'd like access, please [**get in touch**](mailto:Tally@cscale.io)**.**

### What you need

* **Windows.** Tally 2.0 is a Revit add-in and runs only on Windows.
* **Revit 2024, 2025, 2026 or 2027.** Earlier versions aren't supported.
* **A C.Scale login belonging to a paid organization.**

Tally 2.0 runs alongside Tally 1.0. Installing it won't disturb an existing Tally 1.0 setup, and both can sit in Revit at the same time.

### Download the installer

[**Download the Tally 2.0 installer here**](https://ow1lorhogychy37d.public.blob.vercel-storage.com/Tally2_26.09.04.09.msi).

### Run the installer

Close Revit before you begin. Note that add-ins installed while Revit is running may not appear until it restarts.

Double-click the installer and follow the installation sequence.

![The first page of the installer.](https://docs.cscale.io/images/tally-getting-started-1.png)

> Note that you may see a message about an unknown publisher or an unverified source. This is expected during the beta. We're still completing the plug-in's digital signing.

### Open Tally in Revit

Reopen Revit. Tally appears in the top ribbon under **Add-Ins → Tally 2.0**.

![Tally 2.0 in the Add-Ins tab of the Revit ribbon.](https://docs.cscale.io/images/tally-getting-started-2.png)

### Sign in

Log in with your existing C.Scale credentials.

Once you're logged in, select the organization you want to work under. If you belong to more than one, choose the paid organization you're running Tally through.

You're in. Next, see [**Modeling in Tally 2.0**](https://docs.cscale.io/tally-2-0-users-guide/modeling-in-tally.md) for the workflow, or the [**Tally 2.0 FAQ**](https://docs.cscale.io/tally-2-0-users-guide/faq.md) for short answers.