There are very few banks out there that will allow a seller held second without you coming out of pocket or using some sort of collateral.  

Even if I was the senior lender for one of the new developments, in a downside scenario I wouldn't know what to do with the land / the half-finished or finished (but unsale-able for whatever reason) inventory.Therefore - I don't want to invest / make a loan in the development JV itself - I would rather make a loan at the parent-co level where there is collateral in the form of completed properties that are generating rental cash flow - they do have mortgages on them. 

Yishi Zuo, I understand your desire for collateral.

@Wil Reichard It seems the asset/collateral is the issue here, not the amount you have invested.

Talk with your current lender and cross collateralize the existing properties with the new property.  

Essentially no income details are required and the loan is based off of the collateral of the property and income, calculated using the active rents, appraisal rent schedule or even STR income or projected income.

I did pledge assets to cross collateralize.

But since private money is relational based versus purely collateral based, you'll need a track record to prove yourself.

Ideally, if they have other properties, getting collateral on that as well. 

The only way I thought I could protect myself better in this situation if I were to decide to move forward would be to cross collateralize by taking a first lien on a separate property of the borrower.