The current plan is to have about a two year waiting list. So the decision point is to have enough applications to cover two years of development. For the signup list I am arbitrarily guessing about a 50% conversion rate. Once we have signups we can contact the families to better understand the commitment level and the details of the desired housing.
For the estimated $200,000/year income requirement, and $4,000/unit that means 50 units/year, so we need 200 families to sign up initially and 100 families to commit.