Understanding How Roofs Generate Above Curved Walls

Reference Number: KB-03019
Last Modified: July 19, 2021

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


How can I control how the roof planes generate over my curved wall?

exterior view of small victorian home with curved porch and roof


Automatically generated roof planes are placed over curved walls at specified increments.

In the Build Roof dialog on the Roof panel under Options, you can specify the degree increments for the roof over curved walls, from 6° to 90°. The lower the number, the more roof sections are created over the curved wall.

The following illustrations show a roof created at two different curved increments:

  • 15°

  • 30°

Concave Curved Walls and Roofs

Regular roof plane sections can also generate over concave curved walls. For roof sections to generate over a concave curved wall, the sections’ baselines must be longer than the Minimum Alcove Size value on the Build panel of the Build Roof dialog.

If the baselines are shorter, the automatically generated roofs are simplified by either:

  • Ignoring the curved wall, as if the walls on either side extended to their meeting point.

  • Spanning the concave curved wall with a straight Baseline and produce a roof plane for it from that.