I have a property there and the regulations are a bit of a disaster depending on where exactly you go so just be careful on that especially if you are not owner operated.

I want to ensure that I follow any sort of regulations and safety standards but I don't know where to even start or know how to estimate rough costs.

Happy to provide some insight on the state of the STR/MTR market here as regulations change drastically from city to city. 

I saw those regulations too and forgot when I was considered from an investor's perspective.

Also keep in mind that adding sqft will likely increase your taxes and local regulations might limit the use of the ADU. 

Louis offers affordability, cash flow potential, and emerging market opportunities but also presents management challenges, unfamiliar markets, travel costs, local regulations, and crime rates.

The laws apply to owner occupant but puts fear of regulation into any lender. 

Seattle has become more lenient on ADU regulations because of the housing shortage. 

note some localized regulations require creativity to envision

Do you know if the city has any STR regulations?