I will need to finance it using a conforming loan or a jumbo.What are the risks of doing this?

@Pete BigitWhen the zoning district uses change as in this example where duplexes are not permitted, but because the rules changed to single family, the old duplexes have become non-conforming (grandfathered).  

Conforming loan amount, FICO 721, single family, non owner should be around 3.625 no points little or no fees - rates change a couple times a day.

@Jonathan LakeSince you are looking for a non Freddie Fannie conforming loan start by researching smaller banks and credit unions around your market area.

Since they are both conforming loans, I assume this is standard for all lenders.

For a house hack you need to decide if you want separate living spaces like a traditional conforming duplex or a house you will share common space with a roommate.

But those are owner occupied conforming rate with much lower risk to a lender.

I checked the law and I would conform to the fire code for a top floor unit.

Any help is greatly appreciated as I have to do this in a conforming conventional to make it work

The key is to figure out what works for you, from a design and cost perspective and of course, making sure it conforms to current market trends and just run with it, making changes periodically as markets change.