You can define the drawn elements by holding them from different points (bottom corner, middle or top corner) while drawing, with the Delta command or by pressing the spacebar on the keyboard.
Location of the Delta Command
You can access it from the wall toolbar.
You can access it from the beam toolbar.
You can access it from the shearwall toolbar.
You can always access it from the ODT door/window toolbar.
You can always access it from the strip footing toolbar.
Before changing the shearwall delta
Changing holding point by clicking the delta button or pressing the spacebar