High-rise achieves six-star energy rating

A 20-storey high-rise commercial office building in the Australian city of Melbourne, Victoria, has become the first in the state – and just the second in the country – to achieve a six-star National Australian Built Environment Rating System (NABERS) energy rating.

The tower, located at 171 Collins Street, is a joint project between Cbus Property and Charter Hall, designed by award-winning architects Bakes Smart, engineered by Umow Lai, and managed by Knight Frank.

A building with a six-star NABERS energy rating emits 50% less greenhouse gases than a building with a five-star rating, which is seen as the benchmark for modern sustainable office buildings. The Collins Street tower saves more than 1.3 million kilograms of carbon dioxide each year, equivalent to 568,000 litres of petrol or 139 homes’ energy use for one year when compared with a building with a five-star NABERS rating.

Opening its doors to tenants in June 2013, the tower features an Australian-first ceiling tile system that absorbs office pollutants and creates a healthier office environment for workers. The building’s grey water treatment programme collects used water and recycles it through the tower’s cooling towers and toilets, offsetting more than 90% of the cooling towers’ water consumption.

The high-performance facade brings light from the sky into the building, also helping in achieving energy-efficiency targets. A radiant cooling and heating system and an under-floor air distribution network provide energy-efficient thermal comfort for occupants, while the air- conditioning system allows large quantities of outside air to be brought into the office space at a low velocity and distributed using natural stratification.