The IBC also has something to say on this subject:
"1006.1 Illumination required. The means of egress, including the exit discharge, shall be illuminated at all times the building space served by the means of egress is occupied.
1. Occupancies in Group U.
2. Aisle accessways in Group A.
3. Dwelling units and sleeping units in Groups R-1, R-2 and R-3.
4. Sleeping units of Group I occupancies.
1006.2 Illumination level. The means of egress illumination level shall not be less than 1 foot-candle (11 lux) at the floor level."
By the way, safety codes do not "trump" energy codes. We need to find a way to satisfy both codes if at all possible. If not possible because of conflicting rules, then the adopting authority needs to be consulted to make the call.