This is normal in a situation involving a permanent “floor-ceiling loan,” where the borrower does not meet a rent-roll requirement, and the first mortgagee funds only a floor amount, agreeing to fund the balance in the event the rent-roll requirement is met within a stated period.
These gap funds are normally evidenced by a promissory note secured by a junior mortgage subject and subordinate in all respects to the permanent loan documentation.
The gap documents usually state unequivocally that, in the event the rent-roll requirement is not met during the rent-roll period, the permanent lender still retains the right on demand to purchase the gap note and discharge of record any second mortgage held by the construction lender.
However, the promissory note for the gap loan should be predicated on the possibility that the rent-roll requirement may not be met, and the terms should include a period of four to five years beyond the rent-roll requirement period, with a high enough interest rate to prompt the developer to refinance whenever it becomes feasible to do so.
Typically rehab lenders will only go to 65-70% ARV (After Repair Value), so if the borrower is bringing 10% into the deal, the gap funder would provide the other 20-25%, and take a 2nd position lien and often a portion of the profit.