All really good info by others above.
The bldg &/or Fire officials are people you should talk to.
The Twp I work in requires (on plans) the egress path(s) with distances, and the locations of the egress lighting and the exits.
The photometrics are overlayed onto the egress paths.
High ceilings may require a 'high intensity' e-light units, as opposed to the regular 'bug eyes'.
Also, within the Bldg Code, it is required to provide emergency illumination 'to the public way'. Easy translated to mean e-lites at the exterior by the designated exit doors. Units with two heads or two bulbs to satisfy the NEC.
