The sinuous organic feel of the letterform dates it to the Art Nouveau era (approx 1890-1910). A bit of sleuthing confirms that the building was completed in 1895, however, I am finding it hard to marry up any of the external architectural features within these images – perhaps at some point it was rebuilt and only the floor was retained...?! Doubt it.
Lots more wordy doorway mosaics here. Or just click on the relevant tags below or to the left