After reading your post about billing, you may have an out to get the other building an address recognized by the city. For emergency dispatch purposes like ambulance calls separate address are required in many states. That has resulted in readdressing streets and renaming streets when another or others exist with the same street name in a county. Someone in the city or county administration is responsible for addressing. That should supersede the city’s recalcitrance.
The city and the US Post Office recognizes it. Even PG&E has been sending separate bills. Only the water and garbage bill refuses to do so. . . because they bill by plot number, not address, even though they had no problem installing two different water meters, which have two separate meter numbers, and have two separate service addresses for garbage service. Idiocy on parade. They have no problem delivering a garbage bin to the correct address (there are two separate driveways). But who ever programmed their computer used the County's plot numbers to establish the account numbers, and they can't even add an A and a B or a -1 -2 to the account number, Brain Dead system.