Iowa Code § 298.21: School bonds.

The board of directors of any school corporation when authorized by the voters at an election held on a date specified in section 39.2, subsection 4, paragraph “d”, may issue the negotiable, interest-bearing school bonds of the corporation for borrowing money for any or all of the following purposes:

1. To acquire sites for school purposes.

2. To erect, complete, or improve buildings authorized for school purposes.

3. To acquire equipment for schools, sites, and buildings.