Such properties would become liable for council tax at the standard rate if they do not meet the letting criteria for classification as non-domestic property, but they could not be charged a premium.
Byddai eiddo o'r fath yn atebol am y dreth gyngor ar y gyfradd safonol os nad yw'n bodloni'r meini prawf gosod ar gyfer cael ei ddosbarthu fel eiddo annomestig, ond ni fyddai modd codi premiwm arno.