# Library

The **Library** tab lists all family types in the user's libraries. If no user library exists upon opening the Library Browser, bimCAT will automatically create the **Default** library and populate it with a few test items.

By default, this library will be created in the following location:\
C:\Users\\\[UserName]\AppData\Local\C-Change Labs Inc\bimCAT \Libraries\Default

In the filesystem a library is a folder containing various RFA and RVT files hosting Revit family types. It is indexed by a special **bimCAT Library Indexer** background application which stores the collected data in a database from where the bimCAT Library Browser could read it.

If for some reason no library currently exists, the **Library** tab will look as follows having only the **Add Library** button.

<figure><img src="https://979736188-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnnfiqwqMJpMWTZIHDlMz%2Fuploads%2Fgit-blob-5290f20b7cce36ce0a78d3f65eb23cb45dd2cfda%2Fimage%20(103).png?alt=media" alt=""><figcaption></figcaption></figure>

The **Add Library** button will bring up the Library Settings window where you could add a library. More information on it is provided below.

<figure><img src="https://979736188-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnnfiqwqMJpMWTZIHDlMz%2Fuploads%2Fgit-blob-f993a8ae3a8c99a686b761a02a8bc0cac0d906ae%2Fimage%20(104).png?alt=media" alt=""><figcaption></figcaption></figure>

Otherwise, the fully functional **Library** tab will be displayed.

<figure><img src="https://979736188-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FnnfiqwqMJpMWTZIHDlMz%2Fuploads%2FYnU6hdrS4r1gvBHlMrh1%2Fimage.png?alt=media&#x26;token=f091597a-e2a9-42b9-bfc0-28b637028204" alt=""><figcaption></figcaption></figure>

Here in the data grid, **the Category, Family** and **Type** columns display the corresponding Revit information. The **Version** column shows off the family type version. The **Library** column specifies the name of the library where each of the family types resides. If elements of a family type were previously exported to the Web App, the corresponding back annotations were added to the family type. The **Web App** column shows whether these annotations are present. If that’s the case, the **Unit** column will display the quantity unit assigned to the family type on the web App, and GWP Achievable and GWP Conservative columns will show off the approximate GWP values for 1 unit of this family type (calculated using the Revit material data and the bimCAT material statistics).

The right pane displays the same family type information as the one in the Current Project tab. The data grid filters also work in the same way.

The toolbar above the data grid hosts a number of buttons which allow you to perform various actions on project family types. Most of them become enabled when data grid items are checked using the checkboxes in the first column.