The 1 Bligh tower in Sydney’s financial district, highly visible when viewed from the Harbour Bridge, is a prominent addition to the city’s skyline. Australia’s first truly “green” skyscraper is a 28-storey tower with a height of 139 m. The tower combines the highest grades of sustainability, spatial efficiency, carefully designed integration into the immediate urban environment and a spectacular view of the harbour. Employees in almost all offices can enjoy the panoramic views due to the elliptical shape of the building. The compact elliptical shape is a result of the goal to maximise views and to simultaneously minimise solar heat gains. In terms of urban planning the building footprint reacts to the special situation around Bent Street where two city grids meet at an angle. The gentle curves of the ground floor naturally connect Bligh Street with the 4 m lower O’Connell Street. The fully public ground floor with the public steps visually extends Farrer Place and has become an intensively used seating area. Due to the carefully considered elevation of the office floors, the public steps are well shaded in summer and nicely warmed in winter. A lobby café, an external coffee point, a childcare centre, bicycle parking spaces and end of trip facilities (lockers and showers) within the “podium” serve tenants and visitors. The openness of the ground floor is continued in the building’s full-height atrium. The atrium allows for views into the office spaces from the glass lifts – as such creating a sense of community between the tenants. The naturally ventilated atrium is beside the fully glazed double skin façade and is one of the main sustainability features. It serves as a cool air pond and also houses balcony workspaces. The double layered façades allow for operable external sun blinds that reduce energy demands significantly while maintaining the view to the Harbour. A “Tri-Generation” system based on natural gas produces cooling, heating and electric power and is twice as efficient as the conventional power grid. In addition, solar thermal collectors on the roof inject high temperature energy into the solar cooling system. A black water recycling system cleans the waste water within the building. To use the full capacity of the plant, additional sewage is “mined” from a city sewer – eventually saving 100,000 litres of fresh water a day. As a result, the building gained the “6 Star/World Leadership” certification in the Australian Green Star system. It is the first office tower in Sydney to do so. It also gained a “5 Star” rating in the National Australian Built Environment Rating System (NABERS).

International competition 2006, 1st prize Execution: 2009 - 2011 Architects: ingenhoven architects + architectus GFA: 45,000 m²

Green Building Council of Australia, GBCA Green Star, six star

This elliptical-shaped office in the heart of Sydney set new standards for sustainability and innovative high-rise design in Australia.

1 Bligh Street, Sydney’s first 6 Star Green Star high-rise building, won the International Highrise Award 2012 during a ceremony which took place in Paulskirche in Frankfurt.

Designed by Germany's Ingenhoven Architects and Australia’s Architectus, the 139-meter-tall and 30 floors elliptical tower was chosen from 26 competitors from 17 countries.

Meshing design and engineering skills, Arup engineering services helped transform a bold architectural idea into a functional building through a close collaboration between German and Australian offices and involving a wide range of services, from façade, electrical and mechanical engineering, through to fire engineering, lighting design and specialist steelwork structures.

Opened in September 2011, this AU$270m structure is a unique landmark in Sydney.

Innovative features include an automated ‘double-skin’ glass façade, a naturally-ventilated 30-storey atrium, and highly-efficient mechanical cooling systems. Through a range of integrated, environmentally-sustainable solutions, the 42,000m2 building is designed to target a 5 Star NABERS energy rating.

New face in town

1 Bligh Street features the first use of a double skin façade on this scale in Australia. The highly effective façade adapts to ever changing solar conditions at each orientation to minimise the solar penetration to the floor and control direct glare. This allowed the use of very clear glass, creating a building which is very transparent from the outside looking in, and from the inside looking out.

The team took a cold-climate, European-inspired façade design and adapted it for Sydney’s hot, sunny environment.

“From the innovative operable double skin façade wrapping the tower, to the 135m tall naturally ventilated central atrium extending from the ground floor wintergarden up to the glazed skylight overhead, the attention to detail is obvious throughout to create an office space of unrivalled quality.”

Kerryn Coker, Arup’s façade engineering specialist

The building has been achieved through the collaborative efforts of Arup, Enstruct, Cundall, Architectus + Ingenhoven Architects, and Grocon on behalf of the client and building owner, DEXUS Property Group, Cbus Property and DEXUS WPF.