What are the rules for a cantilevered addition? I would like to bump out a wall without the complications of a foundation.

Bumping out a wall is not too terribly difficult. However the cantilever aspect requires the floor joist below this room be replaced with longer joists to creat the actual cantilevel.

It depends on how much u want to cantilever.

Rule of thumb 1' out 2' in. New floor beams are bolted together not nailed.

If going out too far can install steel lolly columns for support.

Chuck