No action may be taken under sections 428A.13 and 428A.14 unless owners of 50 percent or more of the housing units that would be subject to fees in the proposed housing improvement area file a petition requesting a public hearing on the proposed action with the city clerk. No action may be taken under section 428A.14 to impose a fee unless owners of 50 percent or more of the housing units subject to the proposed fee file a petition requesting a public hearing on the proposed fee with the city clerk or other appropriate official.