Stair Tool Basics - Bullnose Stair

[Andrea Polgar]

This article outlines how to model a stair with bullnose steps. To see how to place a traditional railing on it, click here.

• Activate the Stair Tool and place any Stair of choice (Bullnose stairs are mostly made of wood).
• Navigate to the floor plan and select the Stair and click on 'Edit' (The Edit button appears in a blue box next to the selected Stair). The Stair is an assembly element in ARCHICAD, so it has subelements. The subelements can be selected and edited one-by-one, if the 'Edit mode' is activated.
• Select the second Tread and make it curved.
• Click on the edge of the selected Tread and select 'Edit segment using tangent' option from the Pet Palette and draw a horizontal line.
• Click to finish the input.

• Let's select the first Tread and add an additional node to its longitudinal side.

• Then extrude the edge between the corner and the new node to the end of the second Tread.

Curve the shorter edge of the Tread the same way as the second Tread was curved.

Adjust the edge of the first step to the right position

• The Treads are ready, now the Risers need to be edited.
• Select the Riser of the first step (dashed line) and stretch it.

• Add a node to the Riser and move it to the right position.

• Drag the endpoint of the Riser in order to make it vertical.

• Curve the Riser using the 'Edit segment using tangent' option from the Pet Palette.

• The same steps should be made with the Riser of the second Step.

• Exit the 'Edit mode' by pressing ESC or clicking on 'Exit Edit Mode' on the blue panel at the left upper corner.
• Another option for creating a Bullnose Stair is to create custom Treads using the Morph Tool and save them as Library Objects (Files › Libraries and Objects › Save Selection › Stair Tread).
• Note: Stair numbering items should be edited as well to get them to the right position. Click here to see how to Edit Stair Symbol Components Graphically.

Check the ARCHICAD YouTube Channel for tutorials about the Railing Tool and the Stair Tool.