ArchiCAD has a separate Corner Window tool.
The Corner Window Settings dialog box is similar to the Door and Window Settings dialog boxes. There is no separate object type associated with the tool; most of the windows in the standard ArchiCAD library can be placed using the Corner Window tool.
Corner Windows are placed at straight wall corners.
Please note:
•Corner Windows cannot be placed in a Profiled Wall.
•Corner Windows cannot be placed in trapezoid or curved Walls.
When you wish to place a Corner Window at a wall corner, you can click anywhere on the wall: ArchiCAD will automatically snap the window to the nearest corner of the wall and create a mirrored copy of it on the adjoining wall. The second window’s parameters and properties are identical to those of the first. Their angle and position are automatically adjusted.
•You can only place one pair of corner windows at any given corner.
•The angle between the two walls cannot be equal to either 0 or 180 degrees.
•The placed windows can be stretched manually and individually without breaking the link between the two windows.
Corner Windows turn into simple Windows if:
•You drag away, mirror or rotate any of the two placed Windows.
•The angle between the two Walls is changed to 0 or 180 degrees.
•One of the Walls is elevated (since Windows are part of the host Walls, the two Windows’ elevations become different).
•One of the connecting Walls is deleted or dragged away.
For more information, see Door/Window Tool Settings.