To create a dormer that consists of a smaller roof with no side walls, modify the roof sketch and use slope arrows.
- Sketch a roof footprint with slope-defining lines, or select an existing roof and click Edit Footprint.
- While in sketch mode, click Modify | Create Roof Footprint tabModify panel (Split Element).
- Split one of the lines in the footprint at 2 points, creating a middle line segment (the dormer segment), and then click Modify.
- If the dormer segment is slope-defining (), select the line, and on the Properties palette, clear Defines Roof Slope.
- Click Modify | Create Roof Footprint tabModify panel (Slope Arrow), and sketch a slope arrow from one end of the dormer segment to its midpoint.
- Click Slope Arrow again, and sketch a second slope arrow from the other end of the dormer segment to its midpoint.
- Click
(Finish Edit Mode), and open a 3D view to see the results.