A savings bank may make, purchase or participate in renegotiable rate or rollover mortgages. The interval between the making of the loan and the first renegotiation of the loan shall be deemed the term of the loan, and each subsequent renewal of the loan shall be deemed a separate term. Requirements of section 505(a)(i)(B) of the act (7 P. S. § 505(a)(i)(B)) that "the terms of the loan require payments which are substantially equal except for the last payment" is satisfied with respect to such renegotiable rate or rollover mortgages if the payments during each term are substantially equal, except for the final payment, even though the payments during one such term are different from those during other such terms.
10 Pa. Code § 13.32