Municipal loans to nonpublic schools for construction or renovation.

(b) Any such loan shall be used exclusively for purposes of construction or renovation of physical facilities of such school for educational purposes. Such loan shall be secured by a first mortgage on school real estate owned by said obligor and further secured by security interest or lien with respect to (1) all capital assets of said obligor held for school purposes, (2) current income on such school's endowment funds to the extent that such interest or lien may be exercised with respect to such income, (3) the proceeds of any fund raising efforts on behalf of such school by such person or persons, board of trustees or similar body. The interest rate on any such loan shall be one per cent in excess of the current borrowing rate paid by such municipality. Such loan shall be amortized in equal semiannual installments of interest and principal over not more than thirty years. (c) In the event of default on any installment for a period of ninety days, the entire outstanding principal balance with interest and all costs of collection including a reasonable attorney's fee shall become due and payable. In such event, such municipality shall commence and continue legal proceedings to collect the amount due such municipality.