Standard Bank Centre, Skyscraper in Johannesburg Central Business District, South Africa.

Standard Bank Centre is a 139 m skyscraper at 27 Simmonds Street and 78 Fox Street in Johannesburg's Central Business District. Its pale concrete facade is crossed by dark window strips, with a glossy dark vertical channel running down the centre. The lower floors step out on projecting ledges while the upper body narrows toward the roof. It has 39 stories, five of them underground, and column-free offices 9.7 m wide.

Construction began in 1966 and was completed in 1968 for Standard Bank, which used the building as its headquarters until moving to a new site in 1990. The design was planned by German architect Helmut Hentrich and Austrian architect Hubert Petschnigg with engineer Ove Arup. The site at 27 Simmonds Street and 78 Fox Street forced a compact footprint, leading to the suspended-floor solution.

The building's nickname, the Hanging Building, comes from its top-down construction: floors were suspended from cantilevered arms on the concrete core, top floors first. The plastic molds used to cast the precast slabs gave them their shape, and the 1.5 m steel girders serve as facade balustrades. Standard Bank occupied it until moving out in 1990.

The tower stands at the corner of 27 Simmonds Street and 78 Fox Street in the CBD. Its 9.7 m column-free office floors are reached by lifts in the concrete core; five of the 39 levels are underground, the lowest two holding the computer and lift control centres. Air vents sit in the corners of the facade, and the 60 cm balustrades let the outer glass be cleaned without a suspended cradle.

The steel girders forming the facade balustrades measure 1.5 m high and 24.6 m long. A slewing crane designed for the project lifted and mounted a quarter of each floor level, and concrete was delivered at night to limit traffic obstruction in the CBD. The 60 cm balustrades let cleaners reach the outer glass pane without a window-cleaning lift.