Zoning - Duplex-Style SFH - What are the Cons?

[Claire D.]

I have kept my eye on the small multifamily market in my area and have found that a handful of the properties listed as MFH's are actually zoned for SFH, such as a duplex-style house with shared utilities, or houses with a mother in law suite. As someone looking to house-hack for now and fully rent out the property in the future - I am considering both AirBNBing or traditional rental - what exactly are the major cons of these properties? The first cons that come to mind are:

- It would be financed as a SFH, not multi - I assume I can't use any of the potential rental income towards my loan qualification ?

- Shared utilities between units would need to be factored into rent, if applicable 

- Code violation fees (?) if someone goes out of their way to report you, or if major work is needed and the city "notices" 

Ultimately I am trying to understand how people that own these properties get away with renting them out, and what risks they face to do so. It seems to be a big "don't ask, don't tell" situation from the research I have done. Any additional insight is appreciated!