Down payment on construction loan.

Long story short. My brother is terrible with money but he makes a nice amount. I have been working with him for the past year to payoff all his debts and all that is left is student loans.

He wants to build but he wont have the 20% to put down. Are there any, fiscally smart, financing options for a new build that don't require the 20%?

Let me add, despite my multiple attempts to have him wait another 18-24 months he is insisting on building now. I've built 2 homes and understand the construction loan process, I just have never done so without putting 20% or more down.