N.D. Cent. Code § 43-07-26
Before undertaking any repair, other than emergency repair, or instituting any action for breach of warranty in the construction of a one-family or two-family dwelling, or an improvement with a value exceeding two thousand dollars to a dwelling, the purchaser or owner shall give the contractor written notice by mail, within six months after knowledge of the defect, advising the contractor of any defect and giving the contractor a reasonable time to comply with this section. Within a reasonable time after receiving the notice, the contractor shall inspect the defect and provide a response to the purchaser or owner, and, if appropriate, remedy the defect within a reasonable time thereafter. The contractor shall provide the purchaser or owner written notice of the requirements of this section at the time of closing for the property or, in the case of an improvement, at the time of completion of the improvement. For the purposes of this section, "reasonable time" means within thirty business days after the notice is mailed or any shorter period of time as may be appropriate under the circumstances.
N.D.C.C. § 43-07-26