renovations that require sprinklers?

We own a four story three family building w an owners garden duplex with two floor-throughs above. If we flip to an owners triplex and garden rental, I think that means we’ll need sprinklers throughout… (There is a fire escape.) Any chance of an exception? From reading old threads here it sounds like not.

What if we renovate the bottom duplex to flip our kitchen up to the parlor floor and otherwise keep the apartments the same–would we still need sprinklers?

Or… if we leave apartments and kitchens where they are, but maybe enlarge the backyard opening on the garden level, or dig out a usable room in cellar to expand the downstairs duplex?

Or… last scenario: make it a one-family and leave the garden level kitchen where it is, so we can use garden as an airbnb/in-law type rental, and not a legally separate unit… is that an option?

What about sprinklers themselves? do they go in every room? do they look like the ones in my office–a pipe below the ceili ng with intermittent sprinkler heads on it? are there ways of hiding them a bit more?

thank you for any advice and info