(a) General rule.--Subject to the terms of section 8247 (relating to special limitation on refunding of funding debt) and to the terms of subsection (b), a local government unit shall not extend the term of outstanding debt through refunding to a maturity date that could not have been included in the original issue, except in the case of an emergency refunding of stated maturity date to avoid a default occasioned by an unforeseen shortage in total revenues proven to the satisfaction of the department upon petition, filed by the governing body of the local government unit, alleging the emergency and the unforeseen loss of revenues. Public notice of the intention to file a petition shall be given by advertisement not less than five nor more than 20 days before the filing thereof. The emergency refunding shall be made only in the amount and with the stated maturity date or dates approved by the department. The first maturity of a refunding issue need not occur until the year after the last stated maturity date of the bonds not called in the series being refunded.

(b) Increasing amount of principal payable.--Except in the case of refundings for the purposes specified in section 8241(b)(1) and (5) (relating to power to refund) and except for emergency refundings approved by the department, no refunding bonds shall be issued which will increase the amount of principal payable, after provision for earlier mandatory calls, in any year or years after the latest stated maturity date of the bonds being refunded, over the amount of the principal which would have been payable on the bonds or notes originally issued for the project in each such year if the original bonds or notes had been structured on a 6% level annual debt service plan to the last stated maturity date of the proposed refunding bonds, computed to the nearest whole multiple of $5,000, as the amounts shall be computed by a financial advisor, other qualified person or public accountant.