Want to Repurpose Parents Land into Multifamily, Where to Start?

[Nick Sullivan]

Out of curiosity, I went to the city planning site where my parents current home is and it turns out that they own the lot behind them as well and had no idea!  There house is in poor shape and I've been suggesting that they consider repurposing the land to replace their home with a few multifamily units. The land is awkwardly shaped but is accessible by two roads.  The city planning department told me that we could place multifamily units on the land as long as it met setback guidelines and access to water/sewage etc.  

The challenge is where do I start?  Would love feedback from anyone that has experience or perspective on this. Should I contact an architect/engineer to give options on how to best use the land? 

I've attached an aerial image of the land. Would love any feedback!