Infrastructure Sustainability Council of Australia

Everything you need to know...

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What is ISCA and the IS Rating Scheme?

The IS rating scheme is a method used by the Infrastructure Sustainability Council of Australia to improve the productivity and liveability of industry and communities through sustainability in infrastructure. IS is a voluntary, third-party assured assessment that evaluates the overall sustainability performance of infrastructure assets.


ISCA is a method of rating and advancing sustainability outcomes in infrastructure by improving the productivity and liveability of industry and communities. The IS rating scheme was launched to promote infrastructure sustainability and is a voluntary third-party assured assessment that evaluates sustainability performance of infrastructure assets.


Infrastructure typically lasts approximately 50 to 100 years. As a rating scheme, (ISCA) strives to cater for the changing needs of society and environmental conditions. Sustainable infrastructure can be defined as designing, constructing and operating infrastructure that allow society to adapt and optimise to changing social, ecological and economic outcomes in the long-term.  


When do I need an IS Rating?

Currently, an IS rating can be applied when a project's total value is greater than $50 million, or when the project falls under any of these catagories.


  • Roads and Bridges
  • Railways
  • Cycleways and Footpaths
  • Port
  • Airport
  • Roads and Bridges
  • Waste Treatment Plan
  • Landfill
  • Waste to energy
  • Electrical Transmission & Distribution
  • Renewable Electricity Generation
  • Gas Pipelines
Public and Open Spaces:
  • Sports
  • Defense
  • Parks
  • Detention
  • Communication networks
  • Storage and Supply
  • Sewage and Drainage


By obtaining an IS rating for your development, you will not only be reducing your carbon footprint, but you will also subsequently be reducing the operational and maintenance costs associated with the project. According to ISCA, since 2019, there have been 63 completed IS rated developments and 81 active ones. In total, they have reduced energy consumption by the equivalent of Brisbane's entire household energy use for a year, and reduced water consumption by the equivalent of 67,000 Olympic swimming pools. 


What is the process of obtaining an IS rating?

The rating is a continous process which requires collaboration of an IS certified rater and an inhouse sustainability officer from start to finish. If an inhouse sustainability officer is not available, Certified Energy can provide the missing workforce.

The process is broken into 4 stages, as below, Fig(1). After the fee proposal has been accepted, our IS rating assessor will guide you through each step of the process. After the design phase, the IS certifier will complete the required certification and reports to ensure that your project will achieve both a 'Design Rating' and an 'As Built Rating'. Once we reach the operation stage, our rater provides the necessary reports needed for 'Operation Ratings'.  


Diagram for obtaining an IS rating



What criteria are considered for an IS rating?

In order to carry out the sustainability objectives set out by the IS rating scheme, four criteria with their own categories within them are considered. They are as follows:


Table of criteria for IS rating

Figure 1: IS Ratings (ISCA 2020)

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What is the difference between ISCA and other rating systems?


The IS rating tool differs from other rating systems such as Greenstar, LEED, WELL and Lifecycle Assessment as a higher level of detailed communication between primary stakeholders, owners and assessors is required during the rating process. Unlike the other rating systems, which have strict and specific compliance criteria, IS rating is less prescriptive and allows a level of flexibility in proving overall compliance. This means that we can make steps to maintain the design integrity of your project whilst determining a solution to allow you to reach your IS rating goals. 


Image of meeting for ISCA



Costing and Time Commitments

Since the methodology used to obtain an IS rating can be so flexible, this means that the time and cost to receive one can also vary greatly depending on the scale and complexity of the project. 
We highly recommend that in order to receive an exact price and time frame for your project, that you contact us and send in your architectural plans and all relevant systems and infrastructure documentation for review and we will aim to send you a quote within the same business day.
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