735 Collins Street

As part of this Collins Square development, A.G. Coombs Projects was appointed to deliver mechanical services to the first commercial office tower, responsible for the installation of new air conditioning systems, and for delivering an integrated fit-out for both the base building and for major tenant the Australian Tax Office.

Using innovative fabrication and installation techniques, A.G. Coombs manufactured the building’s main services riser off-site to reduce site installation time and improve safety. Designed to be installed in 3-floor-high sections, and dropped into the 17-floor riser from above, the frame contains chilled and condenser water, heating hot water, natural gas, fire sprinkler and hydrant pipes, together with outside air and exhaust ductwork risers.

The new frame was constructed in A.G. Coombs’ large integrated prefabrication facility with each section weighing up to five tonnes. Once completed, it was transported by truck to the site and crane-lifted into position.

The original tower design included two mechanical plant rooms, typical for this type of building. A.G. Coombs rationalised the first tower’s plant room arrangement to include all major equipment in the one space.

Delivering the building’s targeted environmental performance was critical across the design, installation and commissioning stages. All five towers have been designed to achieve 5 Star Green Star – Office Design v2 and 5 Star NABERS Energy ratings. The first tower incorporates energy-efficient plant and equipment solutions, including a tri-generation system, with the aim of reducing carbon emissions and the building’s overall carbon footprint.

Collins Square is Australia’s largest commercial mixed use development, promising to change the face of the Melbourne CBD and creating a vibrant new business precinct. With such a big statement having been made, we had to ensure that the design and construction was undertaken to the highest level of professionalism and in accordance with all standards, regulations and environmental requirements. A.G. Coombs is a standout provider of mechanical services, with their integrated procurement and prefabrication approach enabling the off-site design and construction of high quality components that are straightforward to install; which drives reduced cost, build time and Workplace Health and Safety risk.

Ross Walker, Construction Manager, Built

Project Overview

Project Name: 735 Collins Street

Location: VIC

Client: Built

Project Value: $18.9 million

Year Completed: 2012

Project Type

Construction – new build (including prefabrication)


  • Reduced cost, build time and Workplace Health and Safety risk through innovative prefabrication initiatives.
  • Design rationalisation to condense the floor space and increase usable management and storage space.
  • Improve usable space.
  • Project completed on budget.

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