by Lynne Blundell

1 Bligh Street, Sydney: applause for a big step forward in green buildings

FAVOURITES – 21 May 2009 – The official start of construction this month (13 May) on a landmark green building in Sydney’s CBD felt like a good omen. With the cranes that dotted the skyline several years ago all but gone and construction sites pretty much an endangered species, the pouring of the first concrete at 1 Bligh St was like an affirmation that there’s still a heartbeat in there somewhere.

The building owners, the architects, its future tenants, VIPs and media all gathered at the construction site to watch the first concrete slide into a prepared footing. As the grey sludge slid to the ground a small sea of white hard hats bobbed approval and cameras clicked like manic applause.

And applause seemed justified; the building is being heralded as a big step forward in sustainable design, its construction during a global recession a sign of good faith.

Designed to achieve a 5 star NABERS energy rating and Australia’s first 6-star Green Star rating for a high rise, the building is expected to use substantially less energy than a conventional high rise.

The elliptical glass tower is angled on the corner site to maximise both the harbour view and the sun. It will have a double glass skin that allows the sun in while also controlling its heat.

Co-owned by Dexus Property Group, Dexus Wholesale Property Fund (DWPF) and Cbus Property, the building was designed by Architectus in Sydney in collaboration with German firm, Ingehoven Architects. Construction is by Grocon.

Grocon CEO Daniel Grollo was very upbeat about the project, saying it was a great privilege to be involved in such a building.

“In many ways this building sets the agenda – environmentally, through the quality of its design and from a tenant enjoyment perspective.”

Grollo said sustainability was also a key aspect of construction methods. The concrete used contains a much higher percentage of recyclable materials than usual, site amenities are solar powered and 90 per cent of the rubble from demolition would be put back into the site.

Exemplar green building

Architectus director Ray Brown told TFE the project was a big positive for sustainable architecture, particularly in the current environment when so little is being built in Sydney.

He hopes it will be viewed as Sydney’s exemplar green building for the next decade and beyond, pointing out it has many environmental innovations beyond its twin skin:

“There’s the on-site black-water treatment of 25,000 litres of sewage and recycling. We’re also tapping into the city sewer and treating another 75,000 litres a day and using that in the cooling towers and the green wall [in the ground floor plaza] and the toilet flushings.”

The building incorporates a trigeneration system that uses gas and solar energy to generate cooling, heating and electricity. A hybrid cogeneration system is being developed that can use gas to generate energy or can use the 500 sq m of roof mounted solar panels; these panels provide energy to directly power the absorption chiller.

A major feature is an open internal atrium, naturally ventilated via a series of automated glass louvres. Free heating is provided by in-slab pipework supplied with the heat that is normally rejected through the cooling towers.

A hybrid air conditioning system consists of chilled beam cooling for the façade and low temperature variable air volume (VAV) system for the central zones.

At the base of the building will be an open public plaza that the architects envision will be a meeting place for city workers.

Creating sustainable social spaces

German architect, Christoph Ingenhoven, (pictured with Sydney Lord Mayor Clover Moore) told TFE the building represented an evolution not just for sustainability but also for the creation of social spaces

Principal of Ingehoven Architects, Christoph Ingenhoven, told TFE the building represented an evolution not just for sustainability but also for the creation of social spaces.

Ingenhoven is considered one of the world’s leading architects of green buildings. His sustainable projects include Stuttgart Railway Station and Taiwan’s Opera House and he is known for his strong stance against designing buildings for repressive regimes.

He believes the open design of the building will encourage better interaction and communication for the tenants, while the public ground floor plaza, with its living green wall and broad steps designed to double as seating, will provide a pleasant meeting place for workers.

“The open public space is a feature that will work well in Sydney because the CBD is quite small but is densely populated by office workers. That is one of the positives of not having residential in the CBD – in terms of building design we were able to justify the cost of an open public area because it will be well used.

“In German cities and many others in the world it would not be justifiable because such a space would not get enough use. The residential to commercial ratio in the CBD is usually higher  than it is in Sydney,” said Ingenhoven.

He said the building would also feature the work of three international artists, “a great example of art being privately sponsored but publicly accessible.”

The building is targeted for completion by 2011. Law firm Clayton Utz has signed up as anchor tenant, committing to the first 15 floors. DTZ and Savills have been jointly appointed to market the remaining space, which includes a rooftop terrace with views over Circular Quay and Darling Harbour.

A spokesperson for DEXUS Property Group told TFE the remaining space had attracted strong interest from prospective tenants.

lblundell@thefifthestate.com.au

Key Features

  • on-site black-water treatment of 25,000 litres of sewage and recycling, including tapping into the city sewer and treating another 75,000 litres a day for use in the cooling towers and the green wall, and toilet flushing
  • a trigeneration system that uses gas and solar energy to generate cooling, heating and electricity.
  • a hybrid cogeneration system is being developed that can use gas to generate energy
  • 500 sq m of roof mounted solar panels to provide energy to directly power the absorption chiller
  • an open internal atrium, naturally ventilated via a series of automated glass louvres.
  • free heating is provided by in-slab pipework supplied with the heat that is normally rejected through the cooling towers.
  • a hybrid air conditioning system of chilled beam cooling for the façade and low temperature VAV