How hard to change C of O?

How hard is it to change a C of O on a place? In other words, is it something that takes years? Can you always get one or is it subject to the discretion of some entity? In other words, if you wanted to change your place from a 2 to 3 family, or 3 to 4 family (going up in # of families), is that very difficult to do?

I’m just trying to get a general sense – don’t need specifics.

Thank you!

By U510545 |