Row Reference Lines

What they are

The Performance Seating application uses Revit model lines as references for seat row placement. Each row or row section requires a model line drawn in plan and assigned either a Center Aligned or End Aligned linestyle.

The application reads the length of the line and determines the quantity, sizes, and order of seats based on the selected calculation settings. Seats are placed with their center insertion point on the line (for straight segments) or along the arc (for curved segments), with each seat rotated tangentially to the curve at its position.

Alignment types

Center Aligned lines distribute seats symmetrically about the midpoint of the line, providing equal distance between the line ends and the first and last seats. Use this for rows in the center section of a venue.

End Aligned lines place seats starting at the end of the line closest to the assigned focus point. This is intended for rows at the sides of a seating area, aligning them evenly with the inside aisle edge.

Hosting

Revit requires model lines to be hosted to a level or workplane. Row reference lines follow the same rule. It is helpful to ensure each reference line is hosted to the nominal level of the view where the seats will appear, or a workplane in that same view.

Tip

Since model lines are dimensional elements, they can be hidden by floors or other objects when the view is set to anything except Wireframe. A useful approach is to place a workplane above the highest tier elevation and configure the application to look down for floors when setting seat elevations. See Elevation Alignment for details.

Placing reference lines

Reference lines can be placed two ways:

1. Using the Place Reference tool in the Tools panel on the ribbon. This is the recommended method — the appropriate linestyle is applied automatically.
2. Using the standard Revit model line tool. Any model line assigned the correct Center or End linestyle name (as set in Project Defaults) will be recognized by the application. This is commonly used when offsetting from slab edges.

See Placing Reference Lines for step-by-step instructions.

Geometry notes

Any non-closed line or arc may be used as a row reference. A closed circle or full ellipse will not work and will produce an error. On curved references, be mindful of tight radii — the application does not compensate for curves that are too tight for adjacent seat standards to clear each other.

Reference lines should be offset from a step or slab edge by the distance specified in each seat family's PB_Plan_Datum_Offset type parameter (1'-0" for the Generic Fixed Seat included with the application).

Troubleshooting

See the FAQ for common reference line issues, including seats not being placed and seats facing the wrong direction.