Menu Path
Mod-Roof > Drop Eave
What it does
The Drop-Eave command allows you to lower an eave along the full length of a roof plane edge. You specify a horizontal offset distance, and the eave drops down while maintaining the same roof pitch angle.
🔧 How to use it
Select the Drop-Eave command from the roof modification tools
Click on the eave edge you want to drop
Enter the horizontal offset distance in the dialog box
Press Enter to apply the change
🧾 How it works
When you enter a horizontal offset, the software calculates the vertical drop based on the roof plane's pitch. The eave moves along the plane of the roof, maintaining the same pitch angle as the original roof surface.
The eave is projected in the line of the roof plane by the horizontal amount you specify. This creates a net effect of dropping the eave down while keeping it parallel to the original roof plane.
🛠 Calculating specific vertical drops
If you want the eave to drop by a specific vertical amount rather than specifying the horizontal offset, use this formula:
Horizontal Offset = Vertical Drop ÷ tan(pitch in degrees)
Example: To drop an eave by 300mm on a 30° pitched roof:
Vertical Drop = 300mm
Roof Pitch = 30°
tan(30°) = 0.577
Horizontal Offset = 300 ÷ 0.577 = 520mm
Enter 520mm as your horizontal offset to achieve a 300mm vertical drop.
💡 Tips
The command works along the full length of the selected eave edge
The dropped eave maintains the same pitch as the original roof plane
Use the formula above when you need precise vertical drop measurements