The cause of the blaze was not known but media reports said a wood oven may have been to blame.
Hundreds of firefighters tackled the fire which broke out in the early hours of Sunday in the town of Backnang near Stuttgart.
By mid-morning, the fire was under control but not yet extinguished, according to media reports. The Bild newspaper said damages are at a minimum in the six-figure area.
The fire is being investigated but to date there was no evidence of arson.
"There are no indications of arson or a xenophobic motive," police said, adding that there was a German-Turkish cultural exchange association on the
ground floor of the building.