Recommended Practice

Update From GSA and Import From GSA

The suitability of a GSA model for coordination with Revit can be examined using the tool ‘Check Model suitability for BIM coordination’ from the tools menu.

Mapping GSA Sections

Mapping section properties to Revit Family types is the most crucial step in the import. GsRevit can try to find suitable matches for most steel catalogue sections, but for the rest, the best option is to manually load the desired (equivalent) family type before starting the import. During the import process, one can then select the appropriate family type in the drop-downs.

Section Property References

For each section property in GSA, it must be ensured the section is not referred to by elements/members that are both vertical and non-vertical. Sections referred to by both will not be imported.

GSA has a tool that facilitates splitting section properties into Beam(non-vertical) sections and Column(vertical) sections. The command ‘Rationalize sections for BIM coordination’ in the Tools menu examines all sections in the section property table. If any of them is referred to by both vertical and non-vertical entities, the tool creates a new section property and gets the vertical entities to refer to the new section.

Each Revit column, beam and brace is reflected in GSA as a single member or beam element, depending on whether Design Layer or Analysis Layer is selected. Note the following:

Member - Element coordination

It is recommended that the design layer(GSA Members) be used for coordinating with BIM models.

The commands ‘Model | Manipulate | Create Elements from Members’ and ‘Model | Manipulate | Create Members from Elements’ can be used to initially create Members from Elements and vice-versa but subsequent coordination(between the design and analysis layer) will need to be done manually. To assist in checking consistency of section property references, the tools ‘Update Element sections’ or ‘Reset Member sections’ in the Design menu might be helpful.

Creating levels

All the new entities created by GsRevit will map to the nearest level available. Since Revit Columns span between 2 valid levels, it’s important for the levels to properly reflect elevations of the column ends. GsRevit can try and create levels from GSA’s grid planes, but the user can also create them manually before invoking the import.

Preparing for the import/update

1. Ensure if model is fit to be coordinated with Revit by running the ‘Check Model Suitability for BIM coordination’ command. Make modifications to the model if necessary.
2. Open a new Revit model from one of the templates for Metric or for Imperial.
3. If you plan to use grid planes for creating levels, for best results, ‘Level 1’ in the Revit model may be deleted. If not, levels may be defined at appropriate elevations manually.
4. Load the appropriate family types which are used in the GSA model. If a particular section is being used both as a column and as a beam in GSA, make sure to load them separately in the Revit model, under Structural Column Family types and Structural Framing Family types.
5. It’s best to start the import from an ‘Elevation’ view rather than the default 3D view.

The Revit model is now ready for receiving the GSA model file.

Note: After the import process, Revit may display warnings against errors in the models. Choose ‘Unjoin Elements’ in such a situation.