Central Park (skyscraper) - Design

Design

Central Park was the fourth and largest stage in the plan by architects Forbes & Fitzhardinge for the surrounding commercial precinct, which included the AMP Building, the Commonwealth Bank building and the Wesley Centre. The design of the tower changed several times as the prospect of different planning concessions changed. The building as ultimately constructed measures 226 m (741 ft) from St Georges Terrace to the roof of the mechanical penthouse, and 249 m (817 ft) to the tip of its communications antenna.

The tower has a composite steel and concrete frame featuring a pre-stressed, reinforced slip-form concrete core, which is stiffened by an outrigger truss at the top of the tower and at the various side setbacks. At the time of its completion, Central Park was the tallest core-stiffened building in Australia. The core stiffening method minimises the sway of the building in winds, which even after the core stiffening is around 30 cm (12 in) at the tower's top.

The use of a service core structure for the building minimised the number of internal columns were needed, with only two on the largest floors, which maximised usable space. The 1,200-millimetre (47 in) diameter columns for the tower are made of composite steel and concrete, encased within a permanent formwork of Spiroduct tubing. The pre-cast floor slabs are supported by fire-treated steel beams and provided with a composite action by in-situ topping.

The profile of the building has multiple setbacks, to provide for variable floor areas to cater to the needs of different tenants. The plan of the tower is based upon a square, with triangular wings extending from opposite sides. The building was oriented to make best use of the relatively narrow frontage onto St Georges Terrace. The tower is clad with aluminium and glass curtain walls. The building has 5,000 sheets of glass, which get cleaned twice per year. Because of high winds, it can take up to 3 months to complete one window-washing circuit of the building. To clean the exterior faces of the building, the window cleaners have to move vertically over 10 kilometres (6.2 mi).

Central Park was noted upon its opening for being technologically advanced, with "fully computerised air conditioning", which uses data from 1,400 sensors on each floor to regulate temperatures in an energy-efficient way. From its uppermost floors, there are views out to Kings Park and the Indian Ocean. However, members of the public are not permitted to observe from the building except on designated charity days.

The podium of the building is clad with stone to complement the surrounding street frontages, and the foyer is decorated with murals by artist Brian McKay on 223 m2 (2,400 sq ft) of aluminium wall panels. In addition to the 64,000 m2 (690,000 sq ft) of office space, 3,000 m2 (32,000 sq ft) of retail space and 1,030 basement car-parking bays in the project at completion, the site also includes a 5,000 m2 (54,000 sq ft) landscaped park, which leads towards the intended focal point of the precinct, the restored Wesley Church on the opposite side of Hay Street. The architects intended the park to act as a "breathing space in the hard linear nature of the Hay Street Mall". The park contains sunken seated areas and raised grassed areas, as well as a fountain as the centrepiece. There is also a fountain and a large plaza area which provides a pedestrian thoroughfare to St Georges Terrace. It has been variously described as "magnificent", "one of the few green strips in the city outside the grassed area on the river foreshore", the "green lungs of the city", and "a backyard-sized patch of grass".