After the death of Hac? Omer Sabanc? in 1966 Atli Kosk began to be used permanently as a home by Sak?p Sabanc?, the eldest of the family, and for many years housed Sak?p Sabanc?'s rich collection of calligraphy and paintings. In 1998, together with its collection and furnishings, the mansion was allocated to Sabanc? University to be transformed into a museum.