Along with this, I feel that it's very important to a petrabbit's emotional health to have close daily interaction with his/herowner(s). I consider my bunny a "companion" animal and by myperspective he can only be a companion if he's in the house interactingwith my family and me.
Finally, I know of at least three grisly stories where rabbitsof people I know died violent deaths because they were keptoutside. They literally were easy prey because of this.