Mr. Justice Woodward
delivered the opinion of the court, January 6th 1876.
The answer of the court below to the plaintiff’s second point was a statement in effect that no proof had been given to show a breach by the defendant of his covenant to improve the premises demised by the lease of the 3Íst of March 1873. The bill of exceptions has dwarfed the proportions of these cases into an outline so *466meagre as to make a resort to the general evidence indispensable to an intelligent view of the questions raised and tried. It appears from this evidence that the defendant undertoook to make the improvements which the terms of the lease required. It was alleged as ground of defence, and several witnesses testified, that the additional story stipulated for was added to the hotel building, operations having been commenced in May 1873, and continued at least until some time in June. It was claimed that the carpenter and mason work had been completed, and that the roof had been tinned as promptly as possible. The five rooms into which the additional story was divided had not been finished, but there was evidence that the plaintiff had interfered to prevent access to them by the workmen. It would seem, therefore, that the question presented to the jury was one of perfect or defective execution of a contract, and not one of its performance or non-performance. The general charge is not in the record. All that is properly here for review is the request of the plaintiff for instructions .that if the plaintiff had refused or neglected- to perform his covenants he could not recover rent, and the answer of the court that there were no circumstances given in evidence to justify an affirmance of the point. Upon the real issue tried, it is to be assumed that the cases were properly submitted. The principles of law which control the rights and duties of parties to contracts where questions of perfect, substantial, defective or deficient performance arise, or where performance by one party is prevented by the fault of the other, are well settled by a class of authorities to which Harris v. Liggett, 1 W. & S. 301; Martin v. Schoenberger, 8 Id. 367; Bryant v. Stilwell, 12 Harris 314; Snodgrass v. Gavit, 4 Casey 221; and Miller v. Phillips, 7 Id. 218, belong. In the absence of complaint on this subject, it can only be taken for granted that these principles were justly applied. Defined within this limit as the issue apparently was, there was no room for, the application to it of the principles decided in McClurg v. Price, 9 P. F. Smith 420, where there had been no pretence of the performance of bis covenants by the lessor; and the effect of that decision on Obermeveru. Nichols, 6 Binney 159, and Fairman v. Fluck, 5 Watts 516, it is not now requisite to consider.
The second error is assigned to the rejection of the offer of the plaintiff to prove the daily rental value of the rooms of which he was deprived by the fault of the defendant. This offer was too vague. It may have had reference to the rooms in the fourth story which the plaintiff had covenanted to build. In that case it was incompetent, for it would have introduced into the trial an element too partial and inadequate to meet the exigencies of the issue. In every case of this kind, the proper measure of damages is the difference between the value of the premises in the state in which the tenant takes them, and their value with the covenanted improve-*467merits made. But evidence had been given to show that the plaintiff had been deprived of the use of rooms in the lower part of the house in consequence of the falling of a chimney, alleged to have been caused by the defendant’s workmen. Proof of the fact of the accident was apparently admitted without objection. Whether defence to the extent of the injury caused by it could be set up in these actions of replevin, need not be now discussed. The offer was ambiguous, for it could refer ■ to either of two sets of rooms. Even if it referred to the lower rooms, it presented the defence in an objectionable form. For both reasons it was properly excluded.
The third and fourth assignments may be considered together. On the trial, the court admitted, under exception, evidence on the part of the defendant of the rental value of the bar-room, with a license, separate from the. rest of the house. To rebut that evidence the pláintiff offered to show that be had engaged permanent boarders for the five rooms on the fourth story as soon as they should be finished, and this offer the court rejected. If evidence of the rental value of the bar-room was rightly received, the principle is not apparent that would warrant the rejection of evidence of the rental value of the rooms in the fourth story. But in each instance the evidence was incompetent. If the contract between the parties had been complied with substantially by the defendant, and such defects of performance only had been shown as could be compensated by damages to be found by a jury, those damages were to be assessed in each of these suits for the respective period for which the rent in each was claimed to the extent of the loss to which, for that period, the plaintiff was subjected. Proof of the rental value of the bar could not elucidate the issue, for to that source of profit the lease had given the plaintiff an unquestioned right. And even if it had been relevant, it violated the rule for the ascertainment of damages in cases of this kind. It was an item of detail selected from the body of the property, and the effect of the proof was to afford the jury the means of making a fresh contract between the parties in lieu of that which they had made for themselves. In fixing values of property, and in ascertaining damages for breaches of contracts like this, the extent of the injury suffered is to be established by general evidence of such values and a general estimate of such damages. The rule of this court, stated in The Schuylkill Navigation Company v. Thoburn, 7 S. & R. 411, has been uniformly followed and enforced. Fairman v. Fluck, supra, was an action of replevin for goods distrained for rent. The lessor had covenanted to improve the yard of the tavern leased, and had failed to do so. Tn the opinion of. the court, Sergeant, J., stated the measure of damages to be the difference between the amount the property would have rented for with the improvements made, and the amount it would rent for without them. The judge *468added : “ Not only are remote or speculative damages, such as the profits the lessee might possibly have made, to be rejected, but even the proof of a direct loss of business, by showing that a customer went away in consequence of the condition of the yard.” Evidence of merely illustrative individual acts to settle a question of value or a question of damages would be equally inconvenient and unsafe. The value of a tract of land could not be fixed by proof of the price paid for a similar tract, and the rental value of a single room in a hotel could not be fixed by proof of the rent a particular lessee may have offered for it. One party may have been governed by considerations of convenience or necessity, and the other may have acted on some peculiar personal motive, founded on sentiment, caprice or whim. And as the particular circumstances of each transaction would be open to inquiry, litigation under a rule recognising the competency of such evidence, would be most unprofitably and almost indefinitely prolonged. The plaintiff’s offer could not properly have been admitted except as rebutting testimony, and these causes must go back for re-trial in consequence of the reception of the evidence to which the third assignment of error relates, and which it was the object of the rebutting evidence to meet. In reply to the suggestion of the defendant’s counsel that the evidence complained of in the third error was objected to after it was given by the witness, it is enough to say that the court below treated the objection as having been made in proper time, and recognised the right of the plaintiff to an exception.
Judgments reversed, and venire facias de novo awarded in each case.