KS2 – Commercial Office

The Kings Square projects are located in one of Australia’s most significant CBD urban renewal developments and includes five office towers and two residential buildings. Energy company Shell Australia are set to call King Square 2 (KS2) home and signed up for all 11 floors of the KS2 building

Kings Square will be a contemporary green-star precinct and ESD consultants Cundall assigned eTool to complete the Materials Life Cycle credit as part of the Green Star certification. eTool conducted a whole of building Life Cycle Assessment on KS2 (as well as on KS1, KS3 and KS4) and the project earned a 5 Star Green Star “As Designed” Rating by achieving savings on a list of impact categories when compared to the Green Star standard practice reference case.

eTool modelling software eToolLCD is compliant with the international standard EN 15978 methodology and the scope and system boundaries align closely with the requirements for the Green Star Materials Life Cycle credit.

King Square 2 also achieved a LEED BD+C v.3 2009 Silver rating, and used eTool’s Life Cycle Assessment report to demonstrate innovation in design, which awarded the project additional 3 points.

Results Summary

Impact CategoryUnit                  % Saved Against Benchmark
Global Warming Potentialkg CO2e / m2

24 %

Abiotic Resource Depletionkg Sbe / m2

24 %

Euthophicationkg PO4e / m2

20 %

Human ToxicitymDaly / m2

24 %

Project features

Design life

The project was assessed according to the Green Star Materials Life Cycle credit and has a proposed design life of 60 years. Although the building is expected to provide commercial office space for a longer period of time, Green Star requires all buildings that are assessed for the credit to assume a 60 year design life.


Specification of materials with better performance included cement replacement using high levels of blast furnace slag in concrete mix, use of certified timber and minimal use of PVC. The facade was designed for disassembly and reuse at the end of the building life.

Operational Energy

Energy use accounted for the majority of the impacts and the operational energy associated with the HVAC plant was optimised by using high efficiency water cooled chillers.  Daylight sensors and occupancy sensors were used to make sure lighting energy was used only when required.

Benefits of using Life Cycle Design

Using the concept of functional unit (impact / m2 of net letable area) was fundamental in the Life Cycle analysis. This is a vital information to be considered during the design process to maximise building performance and functionality. Reduced number of car park bays improved the overall performance because there were significant savings in materials for foundations and car park structure as well as operational energy for ventilation and lighting.

This assessment was conducted by Henrique.