18.104.22.168. Notwithstanding section 3.6.1, a ladder may be used in an elevator shaft or hoistway to temporarily serve one of the 2 means of egrees provided for in that section, for a maximum height of 2 storeys.
In addition, the ladder may be used upon the following conditions:
(a) the elevator or the hoist shall not be in the process of being installed;
(b) the opening of the shaft at the level of the first landing shall be completely closed;
(c) the opening of the second landing shall allow only the free passage of persons;
(d) the ladder shall cover the opening of the second landing so as to prevent persons from falling;
(e) the ladder shall be built as work progresses, but without adversely affecting construction work.