¶1That the architect’s certificate of completion is an essential prerequisite to recovery by the builder, if his contract so provides, is most firmly settled in, this state (Hudson v. McCartney, 33 Wis. 331; Boden v. Maher, 95 Wis. 65; McAlpine v. Trustees of St. Clara F. Academy, 101 Wis. 468; John Pritzlaff H. Co. v. Berghoefer, 103 Wis. 359, 364; Coorsen v. Ziehl, 103 Wis. 381; Consolidated W. P. Co. v. Nash, 109 Wis. 490); but that there may be excuses for the nonperformance of that prerequisite is equally well established by several of the cases above cited. Such excuse may arise from the misconduct of the architect, as defined in those cases, but more obviously and certainly from conduct of the other party to the contract either waiving or preventing the obtaining of such certificate. Hudson v. McCartney, supra; Wendt v. Vogel, 87 Wis. 462, 466; Wambold v. Gehring, 109 Wis. 122; Diehl v. Schmalacker, 62 N. Y. Supp. 1080; Fitts & Co. v. Reinhart, 102 Iowa, 311; McDonald v. Patterson & Co. 186 Ill. 381. To hold otherwise would be to judicially sanction fraud of the most effective character. The complaint here clearly alleges full performance of the contract, and that the failure to produce the architect’s cer*415tificate is due to acts of the defendants rendering that step impossible. This alleges sufficient excuse, and the absence of such certificate does not defeat the cause of action, otherwise sufficiently stated in the complaint. The demurrer was properly overruled.
¶2By the Court.— Order appealed from is affirmed.