There are two ways to create a hole in a Roof.
1.Select the Roof in the Floor Plan or the 3D window.
2.From the contour polygon (not the pivot polygon!), bring up the pet palette and choose the Subtract from Polygon command.
3.Draw the hole in the Roof.
4.View the result in 3D.
1.Select a Roof.
2.With the Roof tool active, draw a new contour within its boundaries. The new contour will be interpreted as a hole in the Roof.
Note: If you create a hole whose outline intersects the host Roof’s contour or the outline of other holes in the same polygon, ARCHICAD will display a warning message, but the outline of the hole will still be created.