New Construction Duplex or Single Family for investment??

[Zab Khan]

Hi, I'm new to the forum and purchased a residential lot in Modesto which previously had a house on it so which was removed so I'm credited on majority of the fees to build. Since the lot is on a corner, the city will allow a duplex as well. I am a contractor and my initial plan was to build a 1500 sq.ft. spec home but now have an option for a duplex as well.  The area consists of a mixture of both.  Which should I build??