One of Sydney’s business ambitions is to attract the best talent and enterprises in the world. Starting with the Sydney Opera House, completed in 1973, locals recognized that world-class architecture could make the city a destination. Today, its planning authority, the Central Sydney Planning Committee (CSCP) requires that developers hold competitions for major buildings, and encourages local architects to partner with the stars. An independent design panel makes a nonbinding recommendation for the best solution for each contest, but the CSPC makes the final decision on approval.

It seems to be working. Sydney’s newest tower, 1 Bligh Street, is the result of a 2006 competition won by the team of Ingenhoven Architects from Düsseldorf, Germany, and local firm Architectus. Within a couple of blocks are buildings by Foster + Partners, Rogers Stirk Harbour + Partners, and Kohn Pederson Fox Associates. These join a few of the best ’60s and ’70s Modernist office towers built anywhere, designed by the late Sydneysider, architect Harry Seidler.

Australia’s Dexus Property Group put on the contest for 1 Bligh Street. “Our competition brief was very prescriptive,” says head of development Tony Gulliver. “Among other things, we spelled out it would be a highly sustainable building, with a high-quality indoor environment, minimum distances to daylight, and very large floor plates.” There were also city requirements for a podium, a conservative floor-to-area ratio, and for preventing the new building from casting a shadow over a nearby square.

“We had a lot of restrictions and we did not stick to any of them,” says Martin Reuter, project architect for Ingenhoven. “Well, we did respect the building setback lines, but otherwise we decided to give something better to the city than a podium and a tower. And then we would explain to the planning board what we did.” Luckily, the planning board agreed with their proposal, and the podium requirement was waived.

The sloping rectangle-shaped site is located on the corner of an awkward three-block parcel, which is cocked at a 45-degree angle from the rest of the downtown’s street grid; a remnant of a failed Colonial-era attempt at city planning. One advantage of the site is its commanding view of the Sydney Bridge and harbor to the north. After considering a number of schemes, the architects adopted an elliptical plan, with its long side facing toward the harbor. The ellipse gives each office space floor-to-ceiling panoramic views. The building’s post-tensioned-concrete structure is composed of beams that cantilever out from the columns on every floor, minimizing the interior structure; for much of the floor plate, the view is interrupted only by narrow curtainwall mullions.

“The problem,” says Ray Brown, a principal at Architectus, “is that in this part of the world the heat load comes from the north. The challenge is preserving the view without resorting to black glass. That meant coming up with a high-performance façade.” Arup’s Sydney office designed a practically clear, double-walled façade with automated blinds that has a net shading coefficient of 0.15.

The architects chose to limit the enclosed area at the ground floor to about 40 percent of the tower’s footprint, with the upper floors cantilevering out to form a protective overhang. This yields covered space for an outdoor café, an outdoor play area for the building’s childcare center, and curving stairs that cascade down to the street. On warm days the steps have become public space, a haven for brown baggers.

Inside, a skylit atrium, trimmed in glass and aluminum, rises the full height of the building. Air flows through the lobby’s entry doors and through open glass louvers in the exterior walls, so that balcony corridors on each floor can be naturally ventilated. The building is equipped with a trigeneration plant that provides heating, cooling, and power. A blackwater harvesting system processes over 20,000 gallons of water daily, sourced from Sydney’s sewer systems for use in flushing the building’s toilets and in the building’s cooling tower.

The building is packed with costly finishes and many sustainable features, but Gulliver explained that law and boutique finance firms are willing to pay for them: The building officially opened in late August and only has nine floors (out of 28) left for leasing. And in contrast to American developers who build and flip, he says, “It’s a different ownership profile … [in Australia]. Dexus will have this building in our portfolio for decades.”

The CSCP was happy too. It decided that the project’s design excellence merited a 10 percent floor-to-area ratio bonus.

Project Credits

Project 1 Bligh Street, Sydney, New South Wales, Australia
Owners Dexus Property Group; Dexus Wholesale Property Fund; Cbus Property
Architects Architectus, Sydney—Ray Brown (director); Mark Curzon (associate); Ingenhoven Architects, Düsseldorf, Germany—Christoph Ingenhoven (director); Martin Reuter (project architect)
M/E/P and Fire Engineer Arup
Quantity Surveyor Rider Levett Bucknall
Sustainability Consultant Cundall
Structural Engineer Enstruct Corp.
Project-Cost Assessor Davis Langdon
Hydraulics and Fire Consultant SPP Group
Elevator Consultant Norman Disney & Young
Art Consultant Barbara Young
Public Art James Angus
General Contractor Grocon
Project Manager APP
Size 41,806 square meters (450,000 square feet) net leasable area
Cost $667 million Australian (U.S. $712.69 million)(total project cost including site acquisition, demolition, and construction)

Materials and Sources

Ceilings SAS International (office ceiling panels)
G.James (double-wall façade system, louvers); Viracon (insulated glass units)
Glass Sharvain Balustrading (lobby glass walls, glass balustrades)
Hastie Group (chilled beams)
Sharvain Balustrading (atrium skylight)
Vertical Transport
Otis Elevator Co. (elevators)
Water Management
Aquacell (blackwater-filtration system)