Things to know when buying a duplex?

[Michael Faudoa]

Hi everyone, I have a basic understanding of real estate investing but I am still completely new. I'm thinking of purchasing a duplex and I'm wondering what factors I need to consider.
Unit 1 rent is currently $1200 with room to raise
Unit 2 rent is $1250 also with room to be raised
Both units were completely rebuilt in 2016 and look brand new, modern, and great.
My mortgage PITI payment is shaping up to be $2500/mo.
Because I don't have a huge stash of cash, I would be doing 3.5% down with an FHA loan and a plan to refinance to ditch the mortgage insurance a few years down the road.

Currently, the landlord pays for water and sewer. Is it expensive to put a separate meter on each unit? 
Other than creating a budget for vacancies, repairs, and cap ex, is there any other cost of owning a duplex that I'm not thinking of? 
The post is kind of all over the place and I apologize. I'm 25 and very inexperienced, but I love this community and am curious what you all may have to say. Cheers!

[Michele Fischer]

A few other things to keep in mind is that you will be responsible for maintenance of the common areas, like landscaping and snow removal.

Also keep in mind that when you rent a SFH, you often have a renter who will take care of some issues themselves. Duplex dwellers are more likely to call for every little thing, and are more likely to have friction with neighbors since they are sharing walls and space with another renter.

For an exit strategy, SFH can be sold to owners or investors, where duplexes are only an investor play. But we love our duplexes, they also spread the risk across two rent payments (both are normally not vacant at the same time) and generally have higher cash flow.