N.D. Cent. Code § 35-27-04: When lien attaches - Exception - Filing

As against a mortgage given in good faith for the purpose of providing funds for the payment of materials or labor for the improvement, a lien may not be preferred even though such mortgage is recorded after the time the first item of material or labor is furnished upon the premises, or after the actual visible beginning of the improvement unless the person furnishing such labor, skill, or material for such improvement, before the recording of such mortgage, files for record a construction lien.