Most environmental standards used by the property sector measure the operational phase of a property’s life. Existing properties have embodied carbon – the carbon created during their construction phase.
This carbon can be up to 30% of a typical office property’s carbon emissions over its lifecycle, and that does not include a demolition phase. By repurposing and repositioning existing buildings, we conserve the embodied carbon. As far as carbon conservation
is concerned our historic asset strategy of continual improvement is effective.

During FY25 we officially opened our new office building, WS2, in Perth. WS2 is an approximately 9,500sqm premium office building constructed from a combination of steel and timber situated on the existing carpark at Westralia Square, the first of its kind in the Perth CBD. This construction brings a step change approach to minimising embodied carbon across our portfolio, and importantly, in our built environment. The two primary areas of focus were to firstly replace as much concrete as possible with cross laminated timber. Secondly, WS2 borrows structural support from an existing concrete carpark structure beneath it and spare thermal capacity from an adjoining office building (all owned and operated by GDI). These key factors, in combination, have driven an effective embodied carbon reduction of greater than 70% compared to the construction of an equivalent contemporary reinforced concrete building. Based on our experiences from WS2 and our ongoing market assessment we believe that we are market leaders in Perth, in the way we are viewing the opportunities for lightweight steel and timber construction. These developments and reuse opportunities allows us to deliver unique and bespoke spaces that are attractive to tenants at a competitive price. Our focus on embodied carbon hasn’t been to the detriment of our other activities in FY25. During the year we continued to enhance the sustainability credentials of our portfolio by implementing a series of energy-efficient upgrades. These include upgrading HVAC systems such as chillers, pumps, and circulation systems to more efficient models, installing energy strategy control upgrades to building management systems to optimise performance, investing in advanced waste management systems and progressively replacing outdated light fittings. These initiatives reflect our ongoing commitment to strengthen the long-term value and sustainability of our portfolio and resulted in following key achievements:
• Portfolio NABERS energy rating increasing
to 5.08 stars (FY24: 4.96 stars)
• 5 Mill Street NABERS energy rating increasing
to 5.0 stars (FY24: 4.5 stars)
• 1 Adelaide Terrace NABERS rating increasing
to 5.5 stars (FY24: 5.0 stars)
• Westralia Square completing its inaugural
NABERS waste rating and achieving 3.0 stars
• WS2 completing its inaugural NABERS waste
rating and achieving 3.0 stars.
• WS2 base building being 100% covered by
renewable energy for FY25.