Any regional school district which has issued any bonds, notes or other obligations pursuant to any general statute or special act may issue refunding bonds for the purpose of paying, funding or refunding prior to maturity all or any part of such district’s bonds, notes or other obligations, the redemption premium, if any, with respect thereto, the interest thereon, the costs with respect to the issuance of such refunding bonds and the payment of such refunded bonds, notes or other obligations. Such refunding bonds shall mature not later than (1) in the case of a single series of bonds, notes or other obligations being refunded, the final maturity date thereof; and (2) in the case of multiple series of bonds, notes or other obligations being refunded, the final maturity date of any such series last to occur. Such refunding bonds shall be authorized, and the proceeds thereof appropriated for the purposes permitted under this section, by resolution of the regional board of education and shall be issued in the same manner, and shall be subject to the same limitations and requirements, other than those requirements with respect to the manner of authorization of the bonds, as bonds issued pursuant to section 10-56, provided the provisions of section 10-56 regarding limitations on the date of the first maturity, or on the amount of any principal or on any principal and interest installments on any bonds, shall not apply to refunding bonds issued under this section that achieve net present value savings after comparing total debt service payable on the refunding bonds to the total debt service payable on the refunded bonds, after accounting for costs of issuance and underwriters’ discount. Upon placement in escrow of the proceeds of such refunding bonds or other funds of the district in an amount sufficient, together with such investment earnings thereon as are to be retained in said escrow, to provide for the payment when due of the principal of and interest on the bonds, notes or other obligations to be paid, funded or refunded by such refunding bonds and other funds, such bonds, notes or other obligations shall cease to be included in computing the aggregate indebtedness of the district pursuant to subsection (b) of section 10-56.