I usually play Bb as a barre chord at the 6th fret same shape as the F barre chord. I find it easier to maintain the same shape as the F barre.
do you mean I'd Barre the 6th fret instead of barring the 1st?
Yes. Just as Hbriem indicated as his second option:
Code:
e |--i--|-----|-----|-----|-----|
B |--i--|-----|-----|-----|-----|
G |--i--|--m-|-----|-----|-----|
D |--i--|-----|---p-|-----|-----|
A |--i--|-----|-r---|-----|-----|
E |--i--|-----|-----|-----|-----|
6th fret
Try it different ways and see which work best for you.