Opinion by
Mr. Justice Potter,
This was an action of assumpsit in which the plaintiff *118sought to recover a balance of $29,474.21 on a contract for the erection of a building. He also sought to recover an additional sum of $20,000 as damages for alleged breaches of the contract on the part of the defendant. The court below held the affidavit of defense to be insufficient as to the sum of $29,338.07 claimed by plaintiff, but held that an offset of $10,200, as damages for delay in completion of the building, was sufficiently averred, and therefore entered judgment for want of a sufficient affidavit of defense in the sum of $19,138.07. Defendant has appealed, and his counsel contends that no affidavit of defense was required in this case, because, as he says, the plaintiff combined in his declaration, claims for a balance due on the contract, and for damages in their nature ex delicto. In this, however, we think he is mistaken. It clearly appears that the second claim in plaintiff’s statement, is founded upon the violation of an express contract made by the parties themselves. The claim is for damages sustained by reason of the failure of defendant to perform his part of the agreement. Arising as it does out of the agreement of the parties, it is for a breach of contract, and in this is distinguished from a right of action for a tort, which must be based upon the breach of a duty fixed by law, without regard to the will of the parties. We agree with the court below, that there is no mixture here of claims for contract and tort, and that assumpsit was the proper remedy. As to the portions of the affidavit of defense which the court below held to be insufficient, they were merely general denials, and failed to specify any particulars in which plaintiff had failed to comply with the contract. If any of the charges are incorrect, defendant does not point them out, nor does he set forth any additional credits to which he is entitled.
Defendant avers by way of set-off, that the negligence of plaintiff in doing his work damaged an adjoining building owned by defendant. But his averments as to damage are indefinite. He alleged a loss in rentals, but does not give any particulars, or show how the sum claimed is made *119up. Neither does he give any facts upon which his claim for damages to the building is based. His other grounds of set-off are not clearly stated, and no particulars are given as to the amount of damages claimed. He contents himself with naming a large lump sum. In the late case of Law v. Waldron, 230 Pa. 458, our Brother Von Moschzisker states the law as follows (p. 466): “Affidavits of defense should aver the facts depended upon with reasonable precision and distinctness: Markley v. Stevens, 89 Pa. 279. Averments of set-off must be as specific as those used in a statement of claim. The defendant in respect to such a claim is the actor, and the obligation is upon him to aver his set-off in terms incapable of being misunderstood: Loeser v. Warehouse, 10 Pa. Superior Ct. 540. An affidavit of defense is to be taken most strongly against the defendant, for it is to be presumed that he has made it' as favorable to himself as his conscience would allow: Comly v. Simpson, 6 Pa. Superior Ct. 12; Kemp v. Kemp, 1 Woodw. 154.”
Tested by these principles, we think the court below was fully justified in holding that defendant’s allegations of set-off were, with the exception of the claim for damages caused by delay in completing the building, too vague and indefinite to prevent judgment. The question as to damages for delay remains for determination at the trial, in due course. The assignments of error are overruled, and the judgment is affirmed.