The 6 Star Green Star As Built v3 rating achieved by Built for its redevelopment of an outdated 1970s building at 20 Martin Place is partly the result of a detailed materials lifecycle assessment that demonstrated keeping the pre-existing building’s steel structural frame would save 1291 tonnes of CO2.
The project has also achieved a 5 Star Green Star Design and is contracted to achieve a five star NABERS rating.
Originally, Built had contracted to deliver the building at 5 Star Green Star As Built, but was able to get to 6 Star without adding any additional capital costs for the client, Pembroke Real Estate.
The $110 million project achieved 10 out of 10 possible innovation points, eight of those point through meeting innovation challenges including more than half of the paints used in the finishes containing virtually zero volatile organic compounds, educating contractors on sustainability and undertaking a materials lifecycle assessment.
The EN15978 compliant LCA showed the value of retaining the building’s 22-storey steel frame, and that replacing 30 per cent of cement with fly ash would further reduce embodied carbon by 2809 tonnes of CO2e.
It also identified energy-saving initiatives that will reduce the building’s operational carbon emissions to a total of 107,000 tonnes over the next 60 years.
These include LED lighting installed to all office floors; a 100 per cent fresh outside air ventilation system combined with a chilled beam system at the perimeter of each floor; and variable airflow ventilation in the central zone.
The building also has ultra-low flow plumbing fixtures, including in the new showers for cyclists, and 106 cycle parking spaces.
The building now has a new high-performance glass façade; a side core design for more flexible floorplates; increased daylight penetration and indoor air quality; inter-floor connectivity, and new building systems, technology and services.
A diversion from landfill rate of 95 per cent was achieved for all construction and demolition waste. The project was awarded all 77 points in total it claimed in the first round assessment by the GBCA, gaining world leadership status.
Built’s managing director Brett Mason said the sustainability achievements highlighted the benefit of early contractor involvement in projects.
“Early contractor involvement is our preferred method for working with clients to help them solve complex problems,” Mr Mason said.
“In this case, Pembroke bringing us to the table in the project’s early days created an opportunity for quite detailed research and innovation in construction processes, which in turn elevated the number of Green Star points that were earned on the project. It is a great result for both Built and Pembroke.”
The project also won the company an award in last year’s MBA of NSW Excellence in Construction Awards in the Site Safety – Commercial Projects $50,000,001 & Over category, in recognition of its exceptional work on the reconstruction.