At 148 metres, the KölnTurm is the tallest office building in the cathedral city. Following renovation work, the skyscraper has been awarded the international LEED Gold sustainability award for existing buildings. Real estate agent Engel & Völkers has its offices in the building and wanted to introduce energy efficient lighting. With the focus on achieving a particular style, the meeting table in the large conference room is adorned by mouth blown ring luminaires with a diameter of almost 70 cm, instead of standard office lighting. An exceptional feature of the FerroMurano LED Ring of Fire luminaires is the traditionally made Murano glass inset, which is lit from behind by LEDs.