TOPIC:

When placing a wall in the 2D view, the first click specifies the start point and the second click the end point, however if you hold down the Ctrl key before the second click the wall will automatically snap to any angle of 15 degree steps, i.e 0, 15, 30, 45, 60, 75, 90.

The 15 degree step angle is defined in the Grid properties panel.

Also remember to use Ctrl + W to specify the snapping edge of the wall.

Applies to all versions of Visual Building