On the petition of SLS Partnership, Apple Valley, we review a majority decision of the court of appeals reversing an order of the Dakota County District Court for the issuance of a writ of mandamus commanding the City of Apple Valley to permit the continuance of the Partnership's existing nonconforming use of its property as a mobile home park and holding on appeal that the City of Apple Valley may enforce its recently adopted Ordinance No. 515 "as to all mobile homes altered after April 23, 1991." SLS Partnership, Apple Valley v. The City of Apple Valley, 496 N.W.2d 429, 432 (Minn.App. 1993). We affirm in part and reverse in part.