Australian Ethical Investments (AEI) Head Office

Canberra, Australia

Green Star 6 passive design

Key Facts

Green Star Rating

  • Six-Star

To gain a six-star rating

  • 3rd Ever

Energy Savings

  • 75%

Sustainable Cities Awards

  • Winner

IES Consulting optimise energy efficiency and occupant comfort for 3rd '6 Star' Green Star building in Australia, with an estimated 75% in energy savings.

About Green Star
The Green Star rating system, an initiative of the Green Building Council of Australia, evaluates the environmental design and performance of Australian buildings based on a number of criteria, including energy and water efficiency, quality of indoor environments and resource conservation.

About Australian Ethical Investments (AEI)
AEI is an Australian investment company who specialise in environmental and socially responsible investment. It is part of AEI’s philosophy to promote ecologically sustainable and socially just enterprises through careful investment; and also to improve the ethics of corporate Australia. Its new headquarters, the Trevor Pearcy House, was opened by the Australian Greens’ Senator Bob Brown on 23 March 2007. As well as achieving the top 6 Star Green Star rating, it also won a Resource Recovery Award as part of the national Australian Sustainable Cities Awards in October 2007.

The Project
Receiving the 3rd ever 6 Star Green Star certification to be awarded in Australia, the building was refurbished to incorporate a combination of simple passive features that save energy and reduce CO2 emissions. Energy savings compared to the original building are estimated at 75%. Prior to refurbishment the building was a standard two-story 20 year old commercial office of 1100m2.

IES Consulting was employed by Warren Overton, the Green Star Accredited Professional for the project, to optimise through dynamic thermal modelling the energy use and quality of the indoor environment, as well as undertake the analyses required for the related Green Star credit submissions. The building, which received its 6 Star Green Star certification on 19th October 2007, was delivered on a conventional budget (Aus$ 1700/m2) and demonstrates that significant environmental improvements can be achieved in existing building stock, and that simple passive systems can deliver comfortable and productive work spaces. Recognising world leadership, 6 Stars is the highest Green Star rating achievable; it has the same prestige in Australia as a LEED Platinum or BREEAM Excellent rating in the US or the UK.

The Design
In order to achieve such significant energy savings, a combination of the following features were employed:

  • Passive cooling and natural ventilationcombined with a wider thermal comfort band (19-26oC) to reduce demand on mechanical systems
  • Operable double opening double-glazed windows
  • External wall insulation and upgraded roof insulation
  • Increased natural daylight witheffective external shading
  • Addition of 4 thermal/light chimneys
  • Exposed internal thermal mass
  • Automatic night cooling during summer months

IES Consulting were involved in modelling the effectiveness of these features; predicting expected energy savings, checking whether suitable internal conditions would be achieved, optimising the performance of the individual systems and the building as a whole, and determining the best control strategies. In particular, IES looked at the difference a tighter thermal comfort band (21-23oC) would have on energy use, and also advised on the night cooling and window opening control strategies. IES Consulting looked at elements such as solar heat loss and gains, internal air flow rates and CO2 levels, heating and cooling requirements and associated energy use, natural light levels and glare, artificial lighting requirements and associated energy use, as well as the impact of each of these elements on each other.

The Solution
IES’s International Consulting team is highly experienced and skilled in integrated performance analysis. In order to deliver the detailed and comprehensive simulation studies its clients have come to expect IES Consulting uses its unique, world renowned suite of integrated performance modelling tools, the Virtual Environment.

The Australian Green Building Council, whose initiative the Green Star rating system is, called the Trevor Pearcy House: “a leading example of sustainability in the refurbishment of an existing building.” While Collard Clarke Jackson, the architects, and interior and environmental designers, described how the building was sculpted through a cooperative design approach into: “a high class sustainable building which is humane and liveable. It appeals to general instincts of how buildings should feel and look without resorting to gimmickry.”