Planners have overturned a Dublin City Council decision to allow the facade of the former Bewleys on Westmoreland Street to be changed.
TGI Fridays - which has moved into the building - had been given the go ahead to remove its decorative windows.
But An Bord Pleanála said that would impact on the protected structure, hurt the integrity of the Architectural Conservation Area, and set an undesirable precedent.
