What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Non-QM are Generally about 3/4% to 1% higher than Conventional rates, but that really depends on the program, your credit score, LTVs, occupancy status, income documentation type used (if any)...and the list goes on.

I just did a feasibility study on the property and can build a total of 3 ADUs along with the single family home on it. 

It's concerning about the new build prices being lower than resales.

I am actually going by my building today for something else.

It really depends if the previous owner screened the tenants and how they managed the building.

I'm working towards Energy Star in my new 4 unit build because it's fairly easy to get slightly above code and cheap to have the raters come and certify you with the Energy Star label which would add value for the tenants especially for people with alergies or aesthma. 

Working a couple of deals there and looking to expand would like build relationships with a few key people there.  

I’m trying to build different streams of financing, which is why I’m trying to find private money lenders.

I'm looking to build a team to possibly start investing there.