Allow an interest-only period (in months) on the primary loan and/or seller note (#2) before P&I amortization kicks in.
Open questions
- Apply per-loan (primary, seller) — separate IO lengths.
- Math during IO: monthly debt service = principal × (rate / 12). After IO: re-amortize over remaining term.
- Year-1 underwriting and 5-year projections need to handle the IO → amortizing transition (could be mid-year for some inputs).
- Display: show separate "IO debt service" and "amortizing debt service" rows, or a single line whose value changes per year?
- Loan-balance trajectory in projections stays flat during IO — make sure that renders correctly.
Allow an interest-only period (in months) on the primary loan and/or seller note (#2) before P&I amortization kicks in.
Open questions