Use this procedure to offset a structural member from the start point or endpoint of its path. You can remove or change existing offsets, or add new offsets to the start point or endpoint of a structural member. You can also change the structural member start and end offsets on the Properties palette.
A positive start offset value shortens the member on its axis (path), while a negative start offset value lengthens the member on its axis.
Change the end offset of a beam structural member with grips
A positive end offset lengthens the member on its axis, while a negative end offset shortens the member on its axis.
After selecting a grip, you can also enter a value to increase or decrease the start or end offset of the structural member.