[b]Steel Column Extension[/b]

[engcom]

I have a small steel frame structure that needs to be raised a few feet to increase its height. I am considering adding a steel column stub to the bottom of the existing column and bolting the two sections together.

Does anyone have a better way and a sketch of how to do it.

 

[DWHA]

You will need to be sure that the column-column connection is a moment connection, otherwise there will an instability.

 

[Lion06]

If your bases are fixed, I would full pen weld it. If your bases are pinned, make sure the splice can take the moment.
Have you investigated the strength of the existing structure for the extra few feet? That could be adding a decent about to your lateral forces and moments in the members.