> For the complete documentation index, see [llms.txt](https://docs.enercalc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.enercalc.com/efr-user-manual/calculation-types/working-with-beam-calculations/concrete-beam-calculations25/trapezoidal-beam-sections.md).

# Trapezoidal Beam Sections

How ENERCALC for Revit loads and applies a trapezoidal concrete beam family and the limitations on launching such calculations.

Because the default out-of-box family content provided by Revit does not include a trapezoidal beam family adequate for ENERCALC for Revit data exchange, ENERCALC for Revit will automatically load a version-appropriate trapezoidal beam family when a new Revit project (`.rvt` file) is opened. This beam family is visible in the Revit "Project Browser" and may be manually applied to any beam instance using the "Properties" pane:

![](https://4249100372-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgHVzpA9PT0VcuNGp6j39%2Fuploads%2Fgit-blob-e0858fa586878d253f33db066977ed3d0d105ea5%2Fclip0760.png?alt=media)

![](https://4249100372-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgHVzpA9PT0VcuNGp6j39%2Fuploads%2Fgit-blob-2904227d9a1f200ddc3732cc94f317b6bebcb86a%2Fclip0761.png?alt=media)

ENERCALC for Revit supports the design of trapezoidal concrete beams, but does not permit a concrete beam to be joined to the concrete slab:

![](https://4249100372-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgHVzpA9PT0VcuNGp6j39%2Fuploads%2Fgit-blob-0a19f47ea949ba3ee6303d370def28fcc8ab6abc%2Fclip0755.png?alt=media)

Since there is no design counterpart in ENERCALC for a trapezoidal T-Beam or a trapezoidal beam connected to a slab, this configuration will cause the calculation launch to halt with a warning:

![](https://4249100372-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgHVzpA9PT0VcuNGp6j39%2Fuploads%2Fgit-blob-2288b6c7084ae8d119f7083c91380e8f8c88374b%2Fclip0756.png?alt=media)

When a concrete beam calculation loads in the ENERCALC interface, the user will not find options to toggle the beam section type (unlike conventional non-Revit-linked calculations).

If a concrete beam is sent to ENERCALC as a trapezoidal beam, then the calculation will load with only this option displayed:

![](https://4249100372-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgHVzpA9PT0VcuNGp6j39%2Fuploads%2Fgit-blob-3f253b53821c6631e4545c2b60d985c2b9001547%2Fclip0759.png?alt=media)


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