Build a small multi-family, or leave it as a single-family?

[Milagros Aspillaga]

I have a small single-family home in Miami that is currently rented for $1,800 per month. The same family has been there for more than 3 years and they will most likely not renew after next year (2020). It is a centrally located property in a great neighborhood zoned for multi-family homes. I currently owe $130K on the mortgage and am considering taking out a loan (around $350K) so that I can build a new duplex and rent both properties for around $2,300 each.

Is this still considered a BRRR (even though I have owned the property for well over 20 years)? Is this a good investment?