The board of directors of health care facilities and services hospital district no. 1, Linn and Bourbon counties, is hereby authorized to contract with any individual or individuals for the purpose of borrowing money from such individual or individuals to provide money to be used to build an addition to an existing home for the aged subject to such terms and conditions as the parties may specify in the contract. Before any such contract becomes effective, the board of directors shall cause to be published once in a newspaper of general circulation in such district a copy of the contract which shall state, in addition to such other terms and conditions as may be contained in the contract, that the contract shall become effective on the 30th day after the day of publication of the contract unless protest petitions signed by at least 5% of the registered voters of such district are filed with the county election officer of the county in which the home for the aged is located prior to that day. If within such thirty-day period protest petitions are filed with sufficient signers, the contract shall not become effective until the board of county commissioners of the counties in which such district is located call a special election at which the question of whether the contract should become effective is submitted to the electors of such district and a majority of voters voting at such election vote in favor of the contract becoming effective.