Looking for information about changing SFH into Duplex

[John Cannon]

Hi All - Long time listener, first time caller. 

My wife and I are looking to move to Austin, TX in the coming months and purchase a home. We are looking at multi-families as we want to house hack and try our hand at being a landlord, going through the rehab, etc. We have a long list of must haves that I won't get into here, but my ask is around converting single family homes into Duplexes/Triplexes. As there are far more SFH's than duplexes, I wanted to educate myself more here:

-What are the laws we need to be aware of in going through this process?

-What are some of the best practices? 

-Outside of separating water, ensuring new walls are fireproof, what other large expenses should be anticipated?

-Are you able to use a 203k FHA to do this? If not, why?

If anyone has gone through this process, I'd love to learn more from you about your experience!