SKyline sculpture

IN contemporary architecture, design honesty is often the most effective policy. The strength and mass of exposed structural features can have strong aesthetic impact on the presence of a high-rise building the greater the scale, the more impressive the impact.

For Brisbane Square, design and construct contractor Baulderstone Hornibrook created an inner-city landmark with many of its structural elements clearly visible. The development comprises a 40-storey tower, a three-level, low-rise commercial and retail precinct and three basement levels of car parks.

Project director Mike Farrell says the initial schematics and designs for the forward-looking tower were developed by architects Denton Corker Marshall. These were then given structural validation by Qantec McWilliam and transitioned into construction documentation and built by Baulderstone Hornibrook.

Brisbane Square is home to two major tenants. The Brisbane City Council offices are located on floors six to 23 of the tower, while the BCC Library, Customer Service Centre, and Traffic Management Centre have moved into the ground and podium levels. Suncorp is the other major tenant, taking tower floors 24 to 37, some podium space and a banking tenancy at ground level. Around the plaza a series of retail tenancies feature, including food outlets, restaurant-cafes and speciality shops.

"The structure of the tower is essentially its aesthetic expression and it creates a prominent architectural signpost for the area," says Farrell. "At level 29, the high-rise floors start to cantilever over three concrete columns, which rise from level three."

These columns and their supporting spider braces were built by Baulderstone Hornibrook using an innovative, hydraulic, self-climbing work platform complete with safety screens. This is a modern alternative to traditional bird cage scaffolding. The cantilevered floor framing for level 29 was prefabricated in structural steel and then assembled in sections from this working platform. Aluminium cladding was then fixed to the building's lift-core walls by climbing the platform back down around the columns and spider braces towards the podium roof.

Another construction innovation employed by the company was the use of anti-collision technology on Baulderstone's two new Liebherr electric luffing tower cranes. Luffing cranes are specifically designed to work on very tall buildings and in restricted spaces.

"The working radius of the two cranes intersected, and their fail-safe systems allow them to detect the position of machine deck and the jib of each other. If a problem arose, an anti-collision sequence could be initiated decelerating and stopping their movement."

A high-performance glass curtain wall forms the tower facade and includes a veil of perforated aluminium sunscreens which floats over the low and mid-rise sections on two elevations.

"The design included a large plaza which helps link the Queen Street Mall to the Victoria Bridge entry to Brisbane's CBD," says Farrell. "To provide a visual link across the site, the tower floors start at level six, above a full void, with podium buildings inserted as a series of floating boxes below, a clear-glazed foyer in their midst."

The plaza granite paving is also very similar to the existing stone used through the Queen St Mall creating a physical extension of this public space.

The podium buildings at the tower's base are a series of four brightly coloured aluminium clad boxes reflecting the corporate colours of the two principal tenants. Yellow and blue extend the Brisbane City Council's colour scheme while orange and green follow Suncorp's corporate colours.

The building has a strong green focus and a series of Environmentally Sustainable Development initiatives were implemented, including rainwater harvesting for recycling, solar hot water, river-water cooling and responsible material selection. The latter involved specifying materials with low VOC emissions, recycled materials and also renewable timber products.

"Great interest has been taken by the public in the sculptures installed through the plaza level of the tower," says Farrell. "These are a series of balls comprised of steamer segments arranged in geometric patterns and internally lit throughout the evening. They have become popular places to be photographed in the plaza a drawcard for visitors to the city."

For further details, contact Baulderstone Hornibrook, Level 10, 348 Edward Street, Brisbane Qld 4000, phone (07) 3835 0555, fax (07) 3832 0269. Website: www.bh.com.au.

Story by: Trendsideas