Opinion ID: 2167433
Heading Depth: 2
Heading Rank: 2

Heading: Claim of Unilateral Mistake

Text: For the first time on appeal, the tenant argues that the consent agreement should be set aside because of a unilateral mistake of fact. Generally, issues not raised in the trial court will be not be considered on appeal. Aurora Assocs., Inc. v. Bykofsky, 750 A.2d 1242, 1249 (D.C. 2000) (citing Miller v. Avirom, 127 U.S.App.D.C. 367, 369-70, 384 F.2d 319, 321-22 (1967)). Even assuming that the issue were adequately preserved for review, the limited circumstances under which a contract can be set aside for unilateral mistake have not been shown to be present here. See Flippo Constr. Co. v. Mike Parks Diving Corp., 531 A.2d 263, 270-72 (D.C.1987) (adopting RESTATEMENT (SECOND) OF CONTRACTS §§ 153, 154 (1981) as the standard to determine availability of unilateral mistake defense). A claim of unilateral mistake warranting relief requires a showing not only that one party was mistaken at the time of contracting as to a basic assumption having a material effect on the agreement, but also that (a) the effect of the mistake is such that enforcement of the contract would be unconscionable, or (b) the other party had reason to know of the mistake or his fault caused the mistake.  Id. at 272 (quoting RESTATEMENT (SECOND) OF CONTRACTS § 153) (emphasis added). These factors are not present here. The tenant did not claim in the trial court that he assumed mistakenly, at the time he entered the consent agreement, that the landlord was relinquishing any rights he might have to increase the rent. The record shows that the tenant had several rent increases during his tenancy, and there is no suggestion that the landlord had reason to know that the tenant thought, even assuming that he did, that there could be no future increases. There is no showing in this record that it would be unconscionable to enforce an agreement that neither forecloses the landlord's right to charge lawful increases nor the tenant's right to challenge such increases as provided for by law. For the foregoing reasons, we reject this argument.