In this paper we discuss certain strategies for building adapted TTS systems for dialectal or regional varieties from a given standard source. The basic question is how much re-coding is necessary for a given transfer and to what extent it is possible to rely on the speech data alone. It will turn out that there are ambiguities that cannot be resolved without a certain amount of linguistic engineering. For exemplification we present two experiments dealing with Austrian standard German and Viennese dialect on the level of phonetic lexicon and orthography.