Iowa Code Title XIV. Property [Chs. 555-594A] § 562A.36. Retaliatory conduct prohibited

1. Except as provided in this section, a landlord may not retaliate by increasing rent or decreasing services or by bringing or threatening to bring an action for possession after:

2. If the landlord acts in violation of subsection 1 of this section, the tenant may recover from the landlord the actual damages sustained by the tenant and reasonable attorney fees, and has a defense in action against the landlord for possession. In an action by or against the tenant, evidence of a good-faith complaint within one year prior to the alleged act of retaliation creates a presumption that the landlord's conduct was in retaliation. The presumption does not arise if the tenant made the complaint after notice of a proposed rent increase or diminution of services. Evidence by the landlord that legitimate costs and charges of owning, maintaining or operating a dwelling unit have increased shall be a defense against the presumption of retaliation when a rent increase is commensurate with the increase in costs and charges.

3. Notwithstanding subsections 1 and 2 of this section, a landlord may bring an action for possession if: