Brisbane’s King George Square gets royal treatment

June Cummings reports

King George Square is Brisbane’s central civic square in front of the sandstone classical colonnaded Greco-Roman architecture of the City Hall. In recent years, except for occasional festivals, it has become an overlooked open space, traversed by pedestrians heading elsewhere.
But, in the last five years, in conjunction with the massive infrastructure works in its underground carpark for the Inner Northern Busway (INB) link, through to the cavernous subterranean city central bus station, council decided to give the old square a makeover.
Urbis won the revitalisation project in an international design competition. Part of the work was carried out in conjunction with the INB Alliance with the remainder by Kane Constructions.
James Tuma of Urbis, says the challenge was to keep the space open and usable for civic functions re-invoking the importance of the City Hall, while creating a destination of quality in its own right.

Shaded people places
The strategy was all about repair. It meant finding a solution to the blighted Ann Street back end of the square, balance the faade of the City Hall with a contemporary piece of architecture, and bring cafes, and shaded people places into the space.
The 80m x 80m space has a significant level change of 5m. Also the square is like the skin of a drum, with penetrations needed to get people in and out of the huge busway beneath. Ramps and folds then, have determined the architectural theme. The space needed to be active, but not necessarily commercial.
Key elements are the concept of a terrace coming off Ann Street and ramping up with a series of restaurants. Rising over it is a monumental canopy structure, reflective of a Queensland verandah 50m x 15m. Its metal frame and semi-transparent roofing materials are consistent with the city centre Queen Street Mall overarching structures.
The neo-Gothic, red brick and cream, tall spired Albert Street Church, provides a visual point at the high end corner of Ann Street. The elevation of the huge canopy reflects the gable or roof line of the church.
Another major component is an amphitheatre, from which to view events, terraced in shards to deal with the level constraints, and shaded with trees. The graded seating is in timber with stone finishes and black basalt defining the levels. Ten very large trees in this area both soften and provide shade.
Living wall
Against the side wall of the church within the square is another feature, a ‘green living wall’ 50m long x 5m high. It is an integrated self standing wall system of plants pinned vertically.
A large area in front of City Hall retains open space with the addition of some shade trees. The lower Adelaide Street level has a hard edge with two busway entrances – angular shard-like ramp buildings in off-form concrete. A grand ramp leading up to the entrance of City Hall gives a vista through to the Queen Street Mall.
An urban art, water feature 30m long running over precast concrete panels, provides an edge to the canopy and amphitheatre. Runoff water from the canopy is captured in a water tank for reuse. Even the underground car park vents have been turned into art works as glazed shard forms offering transparency.
The heritage listing of the City Hall and its surrounds, even to the kerbing on the garden beds had to be considered. Six palm trees formally placed across the front of City Hall have been retained, but planting in the garden beds has been given a contemporary flavour.
All existing bronze statuary – King George, the lions flanking the entrance, and the Petrie Family - have been mounted on illuminated glass boxes giving elevation to the entrance. Adding to the visual delight after hours, 100 in ground LED strip lights have been grouped outside City Hall.
Big stage set
Overall the square is like a big stage set, with power outlets and other infrastructure on tap, providing a platform for events. The ramp structure accommodates theatrical lighting and the canopy has built-in change rooms.
James Tuma says the overall effect is to provide some simple, elegant, timeless elements that are a contemporary response to City Hall. “We did not want to clutter it with over designed components.”
All the elements tie together the basement level of the bus station, with the car parking level, with the square level with the upper terrace level. For low maintenance, all natural materials have been used, such as recycled timber and natural stone.
One of the biggest challenges, was that the incarnation of a vibrant working urban space, had to be built on an existing 1960s pier structure lid of an underground car park. Construction was not only at surface level, but involved column reinforcements and other engineering considerations for its foundations.
According to project manager for Kane Constructions David Purcell, traffic management was a major issue, with the square flanked by Brisbane’s busiest Ann and Adelaide Streets and fronting City Hall. Surrounded by construction works, people had to have safe passage across the square to buses.
Engineering challenge
Getting materials on and off the site, removing the existing square and exposing the roof of the five level car park beneath, was an engineering challenge. All the hard landscape, top slabs, paving, water features and statue plinths, had been built up over time to an average depth of1m.
With the car park roof slab exposed from excavation, and the existing waterproof membrane compromised, needing replacing, management was required to mitigate the amount of water seeping into the car park and busway beneath, from 18 days of heavy Queensland rain during construction.
All construction machinery and work had to conform to allowable loadings on the carpark roof slab so as not to overload it. Kane Constructions employed a structural engineer to review all the proposed equipment: excavators, breakers, trucks. A real challenge was the erection of the large steel framed terrace canopy.
To complete the work in four weeks a 100t mobile crane had to be located in the square and the route in, temporarily propped. It was brought in at night after the car park closed and after a scaffold crew had worked for 24 hours propping down five levels. The crane and its outriggers were positioned above existing car park columns, then the temporary trusses removed, leaving the crane marooned.
Props on 5 levels
The process was re-applied for the removal of the crane, using Trishore and Slimshore props. Precautions were also taken for the unloading of the structural steel from trucks. Kane Constructions worked out construction methodologies, with engineering approval, which saw the successful completion of the new King George Square structure.
With the structure complete, services such as 100 LED lights and stainless steel pits and grates, had to be installed flush with the vast areas of granite paving with all joints lining up.
The amphitheatre design was highly complex because of its geometry. Kane Constructions employed a licensed surveyor almost fulltime on the project, to provide accurate set down to the nearest millimetre, and fraction of degrees.