Yet, a variance by definition grants authority to the owner to use its property in a manner that otherwise contravenes generally-applicable zoning ordinances. See New London v. Leskiewicz, 110 N.H. 462, 466, 272 A.2d 856 (1970). In effect, the petitioner argues that any business should be permitted to challenge the validity of any ZBA decision to grant a variance to a competitor.