Energy-efficiency design for 6-Star green star office tower

Located in the heart of Sydney’s CBD, the office tower at 1 Bligh Street has set a new benchmark for sustainable office design. Featuring architecturally stunning energy-efficient technologies, the office tower was constructed by Grocon and is owned in partnership between Dexus Property Group, Dexus Wholesale Property Fund and Cbus Property.

“Every aspect of 1 Bligh Street is designed to optimise sustainability and tenant amenity throughout the 28-level development,” Darren Steinberg, Dexus CEO, said.

“As co-owners, we are delighted that our vision to deliver the next generation of sustainable office buildings has been recognised through the achievement of a world leadership 6-star Green Star rating.”

Energy efficiency and building sustainability were a must for the building owners. Designed by Architectus Australia in collaboration with German architect Christoph Ingenhoven of Ingenhoven Architects, the high-rise office tower features a double-skin glass facade. This double-glazed curtain wall outer skin shields the building from the sun, while reflecting natural light into the building.

A naturally ventilated, full-height atrium provides ample natural light to the 1600+ m² office floor plates. The atrium is shaded at roof level by a series of curved solar thermal collects which provide the energy to drive the cooling systems - an advanced hybrid of variable air volume and chilled beam air conditioning technology. This strategy provides enough energy to allow 100% more fresh air to be pumped through the building without any additional running costs, while also providing all the heating for the building.

The commercial office tower also incorporates blackwater recycling. Around 100,000 L of water is recycled at the tower each day, for use in the toilet flushing system. Recycled water is also used to irrigate a 9.7 m high, 40 m long green wall. Water-efficient fittings, rainwater harvesting and fire system water re-use are also part of this system.

To integrate all the energy-efficient systems, Schneider Electric’s EcoStruxure platform was used to achieve the convergence of the building’s energy-efficient technologies. The system provides the owners of 1 Bligh Street with the ability to control and monitor multiple aspects of the building through a single user interface.

At 1 Bligh Street, the EcoStruxure platform converges the Schneider Electric building management system, Clipsal C-Bus lighting control, power metering, access control, CCTV, emergency lighting, blackwater treatment system, trigeneration plant, motorised facade shades, fire systems and lift control systems. The solution links multiple system services over a common IP infrastructure, supporting all connected systems communications via a high-speed dual redundant fibre backbone.

Schneider Electric provides direct monitoring of the facade sun shade system including control and monitoring of the natural ventilation and underfloor heating systems. The solar thermal collects, working with the variable air volume and chilled beam air conditioning, are part of the innovative trigeneration system. This system is centrally monitored and controlled by the Schneider Electric technology. The system uses gas and solar energy to generate energy-efficient cooling, heating and electricity.

“By merging communications, data collection, information sharing and networking into a single, interoperable system, Schneider Electric’s EcoStruxure platform creates efficient, economical building control solutions,” Paul Crothers, Schneider Electric Buildings New South Wales Sales Manager, said.

“1 Bligh Street is a great example of how customers can realise significant cost reductions in the operation and maintenance of their facility.”

Combined, the result of the sustainability features at 1 Bligh Street will be savings for tenants of up to $50 per m² a year in running costs. Compared to a conventional office tower, the building is expected to have a 42% reduction in the amount of CO₂ created.