Expand Architectural Objects, and expand Window Styles.
Select the style you want to edit.
Click the Display Properties tab.
Select Plan High Detail and select Style Override.
If necessary, click .
Click the Frame Display tab.
Select Windows to specify the display properties of regular window frames. Select Corner Window to specify the display properties of corner window frames.
Under Frame, specify the frame type:
Standard. Displays the frame at a standard location.
Offset. Sets the frame to offset from the original location.
Under extension, specify the A-extension value.
Extension is the distance between the window width edge and the frame edge.