Indiana Code Title 20. Education § 20-48-4-3

Sec. 3. (a) If a trustee finds it necessary to erect a new school, the trustee shall procure suitable specifications for the school to be used by the bidders in bidding and in the construction of the school.  If the trustee desires to purchase school furniture, fixtures, maps, charts, or other school supplies, not including fuel and literary periodicals, as authorized by the township board, the trustee shall make an estimate of the kinds and amounts, itemized particularly, to be used by bidders.  If it is necessary to make repairs to a school, other than current or incidental repairs, the trustee shall make an itemized statement of the nature and character of the work to be performed for the use of bidders.

(b) All contracts shall be let after notice is given by publication in accordance with IC 5-3-1.

(c) The township board shall attend the letting.  At the letting, all the work or supplies in any one (1) class shall be included and let in a single contract.  All bids must be in writing and opened and read publicly at the date, time, and place fixed in the notice.  In consultation with the township board, the trustee may take time to examine the bids and determine which is the lowest and best bid.  The board may reject any bid.  The trustee shall endorse either acceptance or rejection on the bids and preserve them.

(d) If a bid is accepted, a proper contract shall then be reduced to writing for the building, repairs, or supplies and signed by the successful bidder and the trustee.  The trustee shall require the bidder to give bond with security to the trustee's approval for the faithful execution of the contract.