(a) Independent or consolidated school districts may borrow money for the purpose of paying maintenance expenses and may evidence those loans with negotiable or nonnegotiable notes, except that the loans may not at any time exceed 75 percent of the previous year‘s income. The notes may be payable from and secured by a lien on and pledge of any available funds of the district, including proceeds of a maintenance tax. The term “maintenance expenses” or “maintenance expenditures” as used in this section means any lawful expenditure of the school district other than payment of principal of and interest on bonds. The term includes expenditures relating to notes issued to refund notes previously issued under this section if the refunding notes are coterminous with the refunded obligation. The term also includes all costs incurred in connection with environmental cleanup and asbestos cleanup and removal programs implemented by school districts or in connection with the maintenance, repair, rehabilitation, or replacement of heating, air conditioning, water, sanitation, roofing, flooring, electric, or other building systems of existing school properties. Notes issued pursuant to this section may be issued to mature in not more than 20 years from their date. Notes issued for a term longer than one year must be treated as “debt” as defined in § 26.012(7), Tax Code.
(b) Notes may be issued under this section only after a budget has been adopted for the current school year.

(c) Notes issued under this section must be authorized by resolution adopted by a majority vote of the board of trustees, signed by the president or vice president and attested by the secretary of the board.
(d) A note issued under this section may contain a certification that it is issued pursuant to and in compliance with this section and pursuant to a resolution adopted by the board of trustees. The certification is sufficient evidence that the note is a valid obligation of the district.