Aleksanterinkatu 48 got its first stone building according to the town plan in the 1840s. Several shifts of ownerships, extensions and alternations took place on the site, and in 1934 The Sigrid Juselius Foundation acquired the real estate deciding in 1954 to erect a completely new building on the site. The new complex was finished in 1958, designed by the K. Simberg architectural office, representing a typical contemporary, rationale and highly adequate office building architecture, 9 floors high with the two lowest floors serving retailing functions. The Gasellen-block including the Juselius-building is surrounded by Pohjoisesplanadi, Mikonkatu; Mannerheimintie and Aleksanterinkatu and is one of the most lively business blocks in Helsinki.

From the year 2010 on A-konsultit has been connected as architects to the works caused by the needs for alternations, extensions and technical updating etc.

The requirements and needs of all the tenants differes highly, but because of its rational basic design the building has turned out to be very resilient and flexible, allowing quite different solutions and unit sizes to be made; there are for instance floorplans containing five different office units, but also units occupying more than one whole floorplan.