Indiana Code Title 32. Property § 32-21-5-12

Sec. 12. (a) An owner does not violate this chapter if the owner subsequently discovers that the disclosure form is inaccurate as a result of any act, circumstance, information received, or agreement subsequent to the delivery of the disclosure form.  However, at or before settlement, the owner is required to disclose any material change in the physical condition of the property or certify to the purchaser at settlement that the condition of the property is substantially the same as it was when the disclosure form was provided.

(b) If at the time disclosures are required to be made under subsection (a) an item of information required to be disclosed is unknown or not available to the owner, the owner may state that the information is unknown or may use an approximation of the information if the approximation is clearly identified, is reasonable, is based on the actual knowledge of the owner, and is not used to circumvent the disclosure requirements of this chapter.