After personally reviewing the property and noticing an issue with the foundation of the pool and pointing it out to them, (I am not even a contractor or an architect and noticed this) they came back two days later with an estimated rehab of 95K!!!

According to drawings from my architect we could potentially fit 37 units into this space of varying sizes.

I am an architect, so new-builds would also be an option (although I would need to reach out for other financing options as I could not afford to do that on my own).

He's even set up free consultations with architects and structural engineers before I've submitted offers so I can know if what I'm planning is even possible.Message me if you'd like his name.

Our architect gave us a not to exceed quote of $6,500 and to date we've gone beyond that.

If the lot is zoned for a multiplex then your next ste would be work with an architect familiar with this type of designing this building.  

A home owner or architect can do it also but I would stay away from it not unless you have experience in doing it. also liability GC have insurance a minium of liability and some cases work comp if need were most home owner do not.YOur local permtting office can tell you what is need in a small stop by or a phone call .

Real Estate Attorney costs, Architect, Builder, Engineer, Permits, Licensing, unforeseen expenses and fees, ect. 

If you want more like traditional style, you can overbuild roof framing.In anyway, you may want to consult a licensed architect (like me :-) and/or structural engineer in your area.  

That is why hiring a good Architect (full disclosure, I'm an Architect) with detailed plans is the best way to go.