normally, the permanent lender's rent-roll requirement involves a period that runs from one to three years. 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. with regard to principal amortization, some gap lenders require none, while others require either partial amortization or amortization to the extent that there is net cash flow to be derived from the project.