Well consider this. The original "Shed" was actually built BEFORE the numbering system
AND before the engineering dash numbers were implemented. Furthermore, the "Shed" was just an out building. A yard barn if you will.
The new "Building" is much more than just a shed! Being constructed in such a way as you would build a "House", it was granted dash one status at the time it was completed.
It is no longer referred to as a Shed. Not only is it a Dash One, I now refer to it as "Bob's Big Blankin'' BUILDING".
I hope that this helps...