They are not to code for a staircase by any means, it is a ladder. Depending on where you are building, this may be allowed as a ladder to a loft, as they are used in this picture. Stairs vs. ladders are very different codes.

The best way to think of putting in a latter like this is to plan on putting in one of those $200 Home Depot attic pull down stairs, then permit that and build something like this.

Ladders to lofts are fun but are generally a bad idea for anyone over 18....

NC 2012 Residential Building Code

Section R311