¶1This suit is by the purchaser of leased premises against the tenant for possession because of nonpayment of rent. The defenses are that all the rents due were not demanded before the bringing of the suit; and that certain improvements' provided for in defendant’s lease were not made, wherefore no rent was due. The court directed a verdict for plaintiff. Defendant appeals.
¶2The first question presented for review is the construction of the clause of defendant’s lease relied upon in the answer, which is, to wit: “To finish the carpenter work in the third story, to put in all necessary water supply pipe and all necessary waste pipe.” The other portions of the lease contain specifications of the plumbing to be placed on the other floors of the house. There is no mention in it of any specifications for such work on the floor. The only color lent to the theory, that the latter part of the. clause, supra, relating to water supply and waste pipes, was intended to apply to the third floor, arises from its juxtaposition to the provi*407sion requiring the carpenter work in the third floor to be finished. This is not, of itself, suffieent to make it applicable to that portion of the house, and, even if it could be held to be so, there is no evidence in the record tending to show that supply and waste pipes were necessary in the third floor of the building. Doubtless, they would have added to the convenience of the lessee in obviating the carrying of water to that floor, but the term of the contract is necessary, not convenient, and circumstances tending to prove what was convenient are not sufficient to create a liability on a stipulation for what was necessary. Hence, there was no error in the construction given by the circuit court to the clause supra, of the lease, whereby it was held not to require the placing of water and supply pipes in the third story of the building.
¶3The next question presented relates to the demand of rent. The petition and proof show that plaintiff demanded all the rent due at the time of demand, except that payable in advance for the current month. It has been expressly held under similar circumstances that a demand for all the rents, except that accruing for an unexpired month at the time of demand, but payable on the first of the month, is suffieent. Mooers v. Martin, 23 Mo. App. 654; Mooers v. Martin, 99 Mo. 94.
¶4Nor is there any merit in the assignment of error for the exclusion of deposition showing the understanding of the tenant and former owner of the terms of the lease. The lease was a written contract and could not be altered, varied or changed, by oral evidence. There being no reversible eri’or in the judgment, it is affirmed.