In an action on such policy it shall only be necessary for the insured to prove the loss of the building insured, and that the insured has given the company or association notice in writing of such loss, accompanied by an affidavit stating the facts as to how the loss occurred, so far as they are within the insured's knowledge, and the extent of the loss.
Iowa Code § 515.137
2007 Acts, ch 152, §24, 63
Similar provisions, §511.35, 514A.3, 518A.19