The incident happened between 4pm on Tuesday, April 27 and 12.20am on Wednesday, April 28.
Unknown offenders broke into the property, which is currently being converted into flats, and stole the items before making off. Both fire places are described as cast iron with inlaid tiles of flowers. One surround and mantle is wooden while the other is grey slate.
Anyone who witnessed any suspicious activity in the area or who has any information on the incident should call Gloucestershire Police on 0845 090 1234, or Crimestoppers anonymously on 0800 555 111, quoting incident 86 of April 28.
