I think a call to the building official to get his/her interpretation/requirements would be the best path forward.

If it truly is just a storage loft (think attic), it would not be considered an occupied space (per the IBC), in which case the IBC's provisions for stairs when serving as a means of egress would not apply. If that is the case, I would follow OSHA's requirements, where the minimum tread depth is 10" and the max riser height is 10". (8" rise and 10" run is pretty standard).

If it is deemed that it can't be considered a non-occupied space, then the IBC's stair requirements would apply and the max rise is 7" and min run is 11".

If I can find anyone at the local building dept. I'll definitely reach out to them. I was thinking the same as you as far as it maybe not being considered an occupied space/means of egress, but I also assumed that there would be something in the IBC for that, but I wasn't finding it. From your reply, can I assume that there isn't anything in the IBC for stairs for other than occupied spaces? Thanks for including the OSHA requirements.

Correct, the IBC does specify any requirements for stairs unless they are being used as a means of egress.

Anecdotally, I would say as soon as you talk about stairs, most building officials want them to meet the requirements laid out in the IBC, even if the IBC does not require that the stairs be provided for a means of egress. i.e. they would rather have no stairs than stairs that don't meet the IBC egress requirements.

Quote:

...they would rather have no stairs than stairs that don't meet the IBC egress requirements.

That doesn't surprise me. Maybe I'll just do a ladder.