In the event an application is made to the Board of Appeals for a variance to enlarge or alter a nonconforming use, the Board shall apply the same criteria in determining the matter as would be applicable if the application had been made for property that was otherwise conforming. For example, if the application is to enlarge a building that already encroaches on a required side yard, the Board shall use the criteria applicable to considering an area variance. If the application is to change the use to another nonconforming use (which is not permitted pursuant to § 270-210 above), the Board shall use the criteria applicable to considering a use variance.