Since I have construction experience, he’s interested in partnering with me to build more units.The property originally cost him $600k, and the projected added value is about $2.4M.

Quote from @Scott Scoville: Just finished one of our bigger projects.

Meaning, your HML should be funding the entire project with nothing out of your own pocket. 

I found that people referred me around quite a bit once I made intial contacts, and that everyone seemed to invest in each other's projects, or at least knew about them. 

Hi Seth,I’m based in Indianapolis but I follow Northwest Indiana closely and do project management on rehab projects across the state.Gary still has a lot of affordable inventory in that $30k–$120k range.

While there are plenty of failed construction projects financed by lenders, what you propose adds additional risk.

Is there a lender out there that can help him turn $50K from equity into cash so we can finish the project? 

Quote from @Bob Ross: Do you building a duplex (2 condos) is a good first development project?

On my first few projects, I underestimated how critical it was to align the lender’s scope with the contractor’s scope word-for-word.

For me, this was an opportunity to back a local project, build new relationships, and gain more experience working with flippers.