Best route to take

[Logan Klinger]

Hey everyone, I’m really new to the real estate space and trying to figure out what road to take on this situation:

My dad had a couple properties when I was growing up and still does. Worked with him to renovate those and get them on the market. But now he has come across an opportunity to build a new magistrate building for the borough he’s invested in. It is just an empty lot sitting around 3.5 acres…paid 140k and will need a fair share of rehab in order to prep the land for these structures and I guess the zoning of this lot allows us the freedom to build “what we want”.  
We are going to build the magistrate building in the near future as that’s guaranteed cash flow every month for multiple years at a time upwards of $1200 a month. So the situation I’m trying to paint is what should we think about doing with the remaining land? I’m on the side of constructing multifamily properties as many that will fit but dad wants to test the idea of a trailer park. Any advice would be super helpful?