Multiplex has broken ground on NEXTDC’s S4 Sydney data centre in Western Sydney. It marks one of the digital infrastructure developer’s largest Australian facilities, and it’s the fourth to be delivered by Multiplex in NSW.
Located at 16 Johnston Crescent in Horsley Park and designed by HDR and Greenbox Architects, the 30,743-square-metre facility spans two four-storey buildings. It is scheduled for completion in mid-2027.
An onsite sod-turning and Smoking Ceremony today marked the commencement, led by Uncle Colin Locke and attended by NEXTDC Group Chief Development Officer Simon Cooper, Multiplex Regional Managing Director David Ghannoum, and Multiplex Regional Director Patrick Murphy.
“This milestone marks the beginning of a significant new phase in NEXTDC’s investment in Australia’s digital infrastructure, reflecting the scale of demand to support growing AI adoption and hyperscale cloud requirements. This new 350MW facility, the first to be approved to directly interconnect to NSW’s Transmission Grid, is sized and designed to deliver highly resilient, high-performance infrastructure that will support next-generation AI compute platforms so significantly contributing to Australia’s digital economy, sovereign capability, and AI future,” said NEXTDC Group Chief Development Officer Simon Cooper.
Declared a State Significant Development (SSD), S4 Sydney will provide critical digital infrastructure to support surging demand for AI computing, cloud services and data storage. It will generate local employment for Western Sydney, with around 1,800 workers onsite during the project’s peak. In addition, the project will stimulate local economic activity, with millions of dollars allocated to procurement from local suppliers.
The project marks the latest milestone in Multiplex and NEXTDC’s six‑year collaboration, spanning a portfolio of major data centres delivered and currently under construction across Perth, Brisbane and Sydney.
“We are proud to continue our partnership with NEXTDC to deliver another highly technical, AI‑ready data centre. For data centre developers, speed of delivery is critical, and our early involvement has enabled us to fast track the construction activity while maintaining a high standard of safety and quality, and ensuring the building is future proofed for future needs,” said Mr Ghannoum.
Alongside the data centre buildings, Multiplex is also delivering a high voltage switchroom building and will facilitate the delivery of a unique 330kV electrical substation, showcasing significant engineering capability.
An onsite sod-turning and Smoking Ceremony today marked the commencement, led by Uncle Colin Locke
The project incorporates extensive modular construction methods, with Multiplex installing prefabricated mechanical plantrooms, electrical switch rooms and main services reticulation pathways. The project also incorporates precast lift cores, columns, OSD tanks and façade elements – requiring some of the world’s largest luffing cranes for installation.
High-performance sustainability features have been embedded throughout the project, including passive design, rooftop solar PV, smart LED lighting, low-GWP refrigerants, low-carbon materials and EV charging provisions.
Water efficiency measures include rainwater harvesting and reuse for irrigation, toilets and cooling towers, while landscape design incorporates native planting, raingardens and a managed ecological zone.
The Horsley Park site was previously a major clay and shale quarry that supplied materials for Western Sydney’s early construction industry – eventually housing convict-era brickworks in the 1830s and later industrial operations such as PGH Bricks. Today, the former quarry is being transformed again as NEXTDC’s S4 Sydney facility.
S4 Sydney has been two years in the making, with Multiplex first engaged to shape the project’s initial design in April 2022. In mid-2024, this progressed into a formal ECI phase – refining design options, supporting the State Significant Development Application process, and ensuring the project’s commercial and technical feasibility. This collaborative effort ultimately enabled S4 Sydney to move into delivery.
Multiplex has delivered four data centres in NSW for NEXTDC, including the S2 Sydney facility in Macquarie Park, Stages One and Two of S3 Sydney in Artarmon, and the S6 Sydney data centre, also in Artarmon. The contractor is currently completing the expansion of Stage Two at NEXTDC’s B2 Brisbane in Brisbane’s Fortitude Valley, and Stage Two of P1 Perth in Malaga, Western Australia.
