Iowa Code § 441.50

The conference board shall have power to employ appraisers or other technical or expert help to assist in the valuation of property, the cost thereof to be paid in the same manner as other expenses of the assessor’s office. The conference board may certify for levy annually an amount not to exceed forty and one-half cents per thousand dollars of assessed value of taxable property for the purpose of establishing a special appraiser’s fund, to be used only for such purposes. From time to time the conference board may direct the transfer of any unexpended balance in the special appraiser’s fund to the assessment expense fund.