Nihonbashi Nomura Building

The Nihonbashi Nomura Building, the former headquarters of Nomura Securities, was designed by our founder, Takeo Yasui. Now, 84 years after it was completed in 1930, it is well loved as a standout building in Tokyo’s Nihonbashi. A validation of seismic resistance performance in 2005 under the Act for Promotion of Renovation for Earthquake-Resistant Structures found that the building fell short of the required performance, and we began remodeling it for seismic resistance. Our deliberations considered the key considerations of “don’t change the exterior,” “don’t seriously impede internal functions,” and “carry out reinforcement works while the building is in use.” Our conclusions led to the adoption of a seismic reinforcement proposal in which each floor of the building was linked to the adjacent New Building, a steel reinforced concrete structure of high seismic resistance performance completed in 1959, to form a monolithic structure. This approach improved the balance of the wall layout and minimized the amount of reinforcement in the Old Building. We carefully installed 300 mm thick reinforcing walls at three locations so that we could preserve the beautiful design on the first floor, in which beam haunches and columns are unified to make beautiful arched forms.