Deal Structure using OPM

[Derek Hizer]

Newbie here! 

I have a good friend who is building an investment property on a piece of land in a successful neighborhood. I'm looking to invest 20,000 dollars of someone else's money in this property. The lender's terms are he will give me the money to invest in this property but wants to double his investment. What is the best way to structure this deal so that the lender doubles his money but I'm able to profit on this deal as well?

Any help is appreciated!