Iowa Code § 643.10: Execution of writ.

The officer must forthwith execute the writ by taking possession of the property therein described, if it is found in the possession of the defendant or the defendant’s agent, or of any other person who obtained possession thereof from the defendant, directly or indirectly, after the writ was placed in the officer’s hands, for which purpose the officer may break open any dwelling house or other enclosure, having first demanded entrance and exhibited the officer’s authority, if demanded.