Many, if not most, employers do not own or control the parking facilities. Even if a name is on the garage, it could be a lease. If your employer does own the parking, a bigger issue could arise getting you a spot to access the power. Ideally the connection is well away from near the door spots. I expect employers are not interested in managing access and will not want to hear complaints about ICE’d situations or EV drivers hogging the spot. They also are not interested in managing complaints by the parking garage employees that want to use the plug for maintenance, the likely reason for the connection being there.
If you can present it as a connection where you or other EV owners would not have exclusive use and that garage/lot employees can use it, disconnecting you if needed, only then make your case that the energy cost is peanuts. Businesses do not want to hear about parking issues. On a long list of petty things that managers handle, parking has to be close to most petty. Reinforcing with them that you understand and have a solution is a tactic that will support your energy calculation.
2013 SL Blue Ocean
Bought used, March 2015 12,764 miles
4th bar drop 56 month, 20,200 miles, AHr at 42.1
Appears fully loaded
Condo home, Using public charge except in emergency
Dallas, TX downtown, shaded non-temp controlled garage