delivered the opinion of the court. The plaintiff, contracted with the defendant to build for him two houses, and brings this action for .the balance of the price agreed on, as. well as for the value of additional work done. The defendant avers, that the buildings were not erected according to contract, and denies the fact of any thing, not included in the original agreement, be:ng executed by the plaintiff. The answer concludes by a prayer in reconvention.
The cause was submitted to a jury in the court below, who found a verdict in favor of the defendant for one thousand four hundred dollars, which was confirmed, notwithstanding an effort on the part of the plaintiff to obtain a new trial. He appealed.
*263From the pleadings, as already noticed, it appears, that the matters in dispute between the parties, were first, whether any part of the work done by the plaintiff was exclusive of the written contract, and second, whether that part of it which is confessedly within the agreement was faithfully and properly executed.
For a proper understanding of the first question, reference must be had to the original contract, which was reduced to writing: by it, the plaintiff contracted to build “ two houses in brick, each of two stories in height, of the extent, and depth, and form, designated in the plan agreed by the parties, and identified with these presents by the signature of bothP In another part of the contract it is stated, that the buildings are to be so completed, that “ on his, the said Suarez, at the time prefixed, handing the key to the said Duralde, the latter may be enabled forthwith to enter, occupy or lease, each building, without any thing more necessary being to be done to either of said buildings, inclosures, or yards
On the plan thus made, a part of the contract, back buildings, embracing a kitchen *264and servants’ rooms, are marked as annexed to the main edifice. But in the description of the manner in which the house should be erected, the size of the rooms, the placing of dormant windows, &c. nothing is said which can "be considered as applicable to the back buildings; on the contrary, every thing specified in relation to the mode in which the work was to be performed, applies exclusively to the front, or main edifice.
in a contract plan is furnished in the contract, pian med by theTestimony was offered and received from a number of master workmen, to shew how they would understand such a contract.— Some swore they would consider themselves bound to perform the work, according to the plan. Others said, they would not. The jury, by their verdict, seem to have adopted the interpretation of the former, and there can be no doubt they decided correctly. The plan, when referred to, and incorporated with the written contract, made a part of it, and the plaintiff, in agreeing to build a house ae-cording to that plan, was as fully bound to kudd every thing specified in it, as if he had expressed his engagement in words. The failure to state how such work was to be performed, cannot discharge him from his obli*265gation. As that part of the building was des- ° , . tined for servants’ rooms and a kitchen, which in general do not require any thing particular in their construction, the presumption is, the parties understood they were to be put up in the ordinary way. But be the reasons what they may, for nothing being said in relation to this part of the edifice, on no rule of construction can the omission to express, in a contract, how work is to be done, release the party who has engaged to do that work, from a performance of it. By one of the rules for the interpretation of agreements, given in the Code, it is enacted that “when the intent of the parties is doubtful, the construction put on it by the manner in which it is executed by both, or by one with the express or implied assent of the other, furnishes a rule for its interpretation.” In this instance, the plaintiff erected the back building without ever stating to the defendant, that it was not included in the original agreement. Such conduct, on his part, would present a formidable objection to the interpretation he now gives to the contract, if its terms were doubtful. But we do not consider them so. We think they *266clearly embraced every thing specified in the p]an> Jjouisiana Code, 1951.
a plea in re-convention need not be answered in writing. An architect may be examined as to the usage of the trade under a contract to-build,but he cannot give his opinion as to the construction of the contract.It has been argued in this court, that the cause was tried without issue being joined; no answer having been put in to the demand ^ ° jn reconvention. But it has not been the practice in our courts, so far as it has come under our notiee, to answer such pleas in writing. They are considered to stand in the same way, as any other matter which is pleaded in avoidance: that is, denied. The 328th and 329th articles of the Code of Practice, sanctions this mode of proceeding. The first permits the defendant to allege new facts in his answer, and make an incidental demand ; and the latter declares, that in such case they shall be considered as denied by the plaintiff.
In the court below, an objection was made to the introduction of architects and builders, to prove their understanding of the contract, 1 ° 7 and it has been renewed here, and much discussed. We think the evidence should not have been received. The witness might have been asked, what was the usage of the trade under such agreements, but he could not give his opinion as to the construction which *267should be given to the writing. That was the province of the court and jury. But as we are satisfied the opinion given by the witness, was the construction which the law puts on the instrument, we cannot remand the cause on that ground.— Douglass' Rep. 527. Starkie on Ev. 1736, in note.
The plaintiff offered testimony, to prove that the work done was worth more than the price stipulated in the contract: his avowed object in offering it, was to show to the jury that his interpretation of the contract was correct. Believing as we do, the contract to be clear and unambiguous, we think such evidence was admissible.
We think the damages given by the jury are not too high, that they conform to the evidence, and it is therefore ordered, adjudged and decreed, that the judgment of the parish court be affirmed with costs.