Opinion by
Trexler, J.,
Section 9 of the Act of June 4, 1901, P. L. 364, provides in regard to municipal claims: “Where claims are *412to be filed to use, the claimant, at least one month before the claim is filed, shall serve a written notice of Ms intention to file it unless the amount due-is paid. Service of such notice may be made personally on the owner wherever found; but if he cannot be served in the county where the property is situated, such notice may be served on his agent or the party in possession of the property, and if there be no agent or party in possession, it may be posted on the most public part of the property.” Section 11 of said act specifies the several items which must appear in the lien. The notice required in the case where there is a use-plaintiff is not included in the matters required to be referred to in the lien. Section 20 of the act makes the lien when drawn in conformity to the act conclusive evidence of the facts averred therein, excepting in .particulars in which these averments are specifically denied in the affidavit of defense.
The defendant at the trial offered tb prové that the notice required by section 9 had not been given to him by the use-plaintiff. This offer the court rejected. At the conclusions of the testimony, the defendant asked for binding instructions in his favor because there was no evidence in the case that the use-plaintiff served a written notice on the owner at least one month before the claim was filed, or his intention to file the lien in question, unless the amount due was paid. There had been no proof that such notice had been served. The court declined to instruct the jury as requested. The position taken by the court was that the defendant,, having filed his affidavit of defense could not, now, take advantage of any technical defense, but- had to stand trial on the merits, citing: Howell v. Philadelphia, 38 Pa. 471; Allentown v. Ackerman, 37 Pa. Superior Ct. 363; Lybrandt v. Eberly, 36 Pa. 347; Lewis v. Morgan, 11 S. & R. 234; Scholl v. Gerhab, 93 Pa. 346; Lee v. Burke & Glass, 66 Pa. 336.
The regularity of the lien is a question of pleading and the cases above cited undoubtedly show that any de*413ficiency as to the form of the lien or the insufficiency of the averments therein contained must be taken advantage of either by a demurrer or a motion to strike off. Where a defendant goes to trial without objection to the form of the lien, it is too late to enter the objection at the trial. The point raised by the defendant is not, however, as to the regularity of the lien. The lien as filed contained every essential statement required by the act. A motion to strike off or a demurrer would have availed the defendant nothing as there was no defect apparent on the record. He could not demur to something that was not on the record or to the absence of something which was not required by the act to be set forth on the record. It is only as to those facts which are averred and are not traversed by the defendant that the latter is bound. The case before us is distinguishable from that of Allentown v. Ackerman, 37 Pa. Superior Ct. 363, and the other cases referred to by the court in this one particular, namely, in all of these cases there was a defect in the lien as filed and such a defect as to which a demurrer could have been filed. The defendant in his affidavit of defense made no reference to a lack of notice neither do we think he was required so to do. No averment in -this regard was made or was required to be made by the plaintiff, neither was the defendant confined to the defense set forth in his affidavit. In the absence of a rule of court, the affidavit of defense when it has prevented a summary judgment, has performed its whole office and is not before the court on the trial unless it is put in evidence, as an admission against the party making it: Flegal v. Hoover, 156 Pa. 276. The Act of 1901 does not change this rule, except as above noted, vvhen facts are averred in the lien and not denied in the affidavit of defense. As to.matters not alleged in the lien, the defendant is not limited to the defense set forth in his affidavit. The giving of the notice by the use-plaintiff to the owner of the property, although not required to be set forth in the lien, is an essential prerequisite to the *414filing of the lien. The defendant offered to prove failure of notice. Having assumed this burden and the court having declined to allow the proof, it would hardly be fair to the appellee, for us to assume that no notice had been given, but the case should be sent back in order that the presence or absence of notice may be ascertained by proof proper.
The third and fourth assignments of error relate to the court refusing defendant’s offer to show the negligent construction of the pavement which was the basis of the city’s lien. The defendant offered , to prove that the improvement made by the use-plaintiff was negligently made and not completed and that by such failure to construct _ the pavement, the defendant suffered damages. Philadelphia v. Bilyeu, 47 Pa. Superior Ct. 148, seems to rule this point. It was there held, following Pepper v. Philadelphia, to use, 114 Pa. 96, that owners of land are entitled to have the contracts for municipal improvements which are paid for by assessments on their lands substantially performed. The specific injury, however, must relate to the portion charged against their respective properties. We think the defendant should have been allowed to prove that the work for which he was charged was not properly done.
The next and last question raised is as to set-off. The use-plaintiff owed defendant certain moneys for stone purchased of him. He was willing at the trial that the amount found to be due should be deducted from the claim, but the court, although the claim of set-off was not objected to, refused to admit it. The municipal claim being in rem and the counterclaim being personal, it might be argued that under the defalcation acts, the one could not be set off against the other, but the rule has been relaxed. As was said in Hilbert v. Lang, 165 Pa. 439, “In general, in order to support a set-off there must be cross demands between the same parties and in the same rights, such as would sustain mutual actions against each other, yet wherever there is the practica*415bility of avoiding circuity of action and needless costs, with safety and convenience to all parties, or where there is a special equity to be subserved and no superior equity of third parties will be injured, a set-off will be allowed upon equitable principles, though the case does not come within the language of the statute.” Set-offs have been allowed in proceedings on mortgage and on mechanics’ liens, but no certificate can be entered in defendant’s favor in such cases: Land T. & T. Co. v. Fulmer, 24 Pa. Superior Ct. 256; Bayne v. Gaylord, 3 Watts 301; Pittsburgh v. McKnight, 91 Pa. 202.
The assignments of error are sustained, the judgment is reversed and a venire facias de novo awarded.