To Create an Interference Condition in a Curtain Wall

Use this procedure to create a stair interference area in a curtain wall. When you add an interference condition between a stair and a curtain wall, a box is cut out around the stair based on the specified headroom height and left and right side clearances for straight and multi-landing stairs or inside and outside clearances for spiral and U-shaped stairs. You have the option of cutting the infills, frames and mullions of the curtain wall.

Specifying the left and right side clearances for a curtain wall interference condition

Specifying the inside and outside clearances for a curtain wall interference condition

1. Create a stair that intersects with a curtain wall.
2. Double-click the stair to open the Properties palette.
3. Click the Design tab, then expand Advanced, and expand Interference.
   

4. Set the size of the interference condition:

   If you want to…	Then…
   specify the height above the treads for the interference condition	enter a value for Headroom height.
   specify the left and right side clearances for the interference condition for straight and multi-landing stairs	enter values for Left and Right Clearance.
   specify the inside and outside clearances for the interference condition for spiral and U-shaped stairs	enter values for Inside and Outside Clearance.

5. Click in the drawing, not on the stair, to remove the selection.
6. Select the curtain wall to intersect, and click Curtain Wall tabModify panelInterference Condition drop-downAdd.
7. Select the stair.
8. Specify whether to apply the interference condition to the infill, frames or mullions of the curtain wall.