Iowa Code ch. 331 § 331.304

If a county proposes to exercise any of the following powers, it shall do so in accordance with the following limitations:

1. The power to act jointly with other political subdivisions or public or private agencies shall be exercised in accordance with chapter 28E or 28I or other applicable state law.

2. The power to adopt, administer, and enforce the state building code shall be exercised in accordance with chapter 103A. The power to adopt by ordinance, administer, and enforce a county building code, is subject to the following restrictions:

a. A county building code shall not apply within the incorporated area of a city except at the option of the city, and shall not apply within a city’s two-mile limit referred to in section 414.23, to the extent that the city has adopted a building code within the two-mile limit.

b. A county building code shall not apply to farm houses or other farm buildings which are primarily adapted for use for agricultural purposes, while so used or under construction for that use.

3. A county shall not license elevator inspectors or regulate elevator conveyances except as provided in section 89A.15.

4. The power to adopt airport zoning regulations applicable to airport hazard areas shall be exercised in accordance with chapter 329.

5. The power to adopt county zoning regulations shall be exercised in accordance with chapter 335.

6. The board may file a petition with the city development board as provided in section 368.11.

7. The power to take private property for public use shall only be exercised by counties for public purposes which are reasonable and necessary as an incident to the powers and duties conferred upon counties, and in accordance with chapters 6A and 6B. Section 306.19 is also applicable to condemnation of right-of-way for secondary roads. Sections 306.27 through 306.37 are applicable to the condemnation of right-of-way that is contiguous to existing road right-of-way and necessary for the maintenance, safety improvement, or upgrade of the existing secondary road.

8. The board, upon application, may grant permits for the use of display fireworks as provided in section 727.2.

9. A county shall not adopt or enforce any ordinance imposing any registration or licensing system or registration or license fees for or relating to owner-occupied manufactured or mobile homes including the lots, lands, or manufactured home community or mobile home park upon or in which they are located. A county shall not adopt or enforce any ordinance imposing any registration or licensing system, or registration or license fees, or safety or sanitary standards for rental manufactured or mobile homes unless similar registration or licensing system, or registration or license fees, or safety or sanitary standards are required for other rental properties intended for human habitation. This subsection does not preclude the investigation and abatement of a nuisance or the enforcement of a tiedown system, or the enforcement of any rules of the department of health and human services or local board of health if those rules apply to other rental properties or to owner-occupied housing intended for human habitation.

10. A county shall not adopt or enforce any ordinance imposing any limitation on the amount of rent that can be charged for leasing private residential or commercial property. This subsection does not prevent the right of a county to manage and control residential property in which the county has a property interest.

11. A county shall not adopt or enforce any ordinance or regulation in violation of section 562A.27B or 562B.25B.

12.
a. A county shall not adopt, enforce, or otherwise administer an ordinance, motion, resolution, or amendment providing for any terms or conditions of employment that exceed or conflict with the requirements of federal or state law relating to a minimum or living wage rate, any form of employment leave, hiring practices, employment benefits, scheduling practices, or other terms or conditions of employment.

b. An ordinance, motion, resolution, or amendment adopted prior to March 30, 2017, that violates this subsection is void and unenforceable on and after March 30, 2017.

13. A county shall not adopt or enforce an ordinance or regulation that prohibits an owner, lessor, sublessor, managing agent, or other person having the right to lease, sublease, or rent out a dwelling unit from refusing to lease or rent out the dwelling unit to a person because of the person’s use of a federal housing choice voucher issued by the United States department of housing and urban development. Such an ordinance or regulation in effect on January 1, 2021, is void and unenforceable on and after January 1, 2023. For purposes of this subsection, “dwelling unit” means the same as defined in section 562A.6.