NEXTDC S4 Sydney: 350MW AI-Ready Western Sydney Mega-Site
Status: Under Construction / Groundbreaking (April 2026) | Location: Horsley Park (Western Sydney), NSW
Project Overview
As of April 2026, NEXTDC’s S4 Sydney project has officially transitioned from planning into active construction, following a formal sod-turning ceremony held in late March. The development represents a major milestone in Australia’s digital infrastructure expansion, positioning S4 as one of the most ambitious data center projects in the Southern Hemisphere. Technically, it is the first data center in Australia approved for direct interconnection with the 330kV New South Wales transmission grid, enabling unprecedented access to high-capacity, high-reliability power required for AI-scale workloads. Designed as a 350MW mega-campus, S4 is purpose-built to support next-generation AI compute platforms, hyperscale cloud deployments, and large-scale data storage architectures.
The facility adopts an advanced modular construction approach, incorporating prefabricated mechanical plant rooms, electrical switchgear assemblies, and standardized data hall units to significantly reduce build timelines while maintaining engineering precision. This modular strategy is aligned with NEXTDC’s accelerated delivery target for a 2027 go-live, ensuring rapid scalability as demand for AI infrastructure intensifies.
Designated as a State Significant Development (SSD), S4 anchors the emerging Western Sydney digital corridor and is expected to become a foundational sovereign-grade infrastructure asset for Australia. Once operational, it will provide a critical landing point for AI training clusters, high-performance computing workloads, and national-scale data sovereignty requirements, strengthening the country’s position in the global AI infrastructure landscape.
Quick Facts
| Field | Value |
|---|
| Project Name | NEXTDC S4 Sydney: 350MW AI-Ready Western Sydney Mega-Site |
| Location | Horsley Park (Western Sydney), NSW |
| Status | Under Construction / Groundbreaking (April 2026) |
| Commissioning | Phase 1 (10MW) Online: Mid-2027 |
| Total IT Load | 350.0 MW (Aggregated Site Capacity) |
| Total Capacity | 124,000 $m^2$ Site Area; Multiple 4-storey buildings |
| Tier Level | Tier IV (Sovereign AI Standard) |
| Project Type | Giga-Scale AI Factory & Hyperscale Cloud Hub |
City Profile
| Header | Details |
|---|
| City Name | Sydney |
| Population | 5.3 million |
| Urban Agglomeration | 5.6 million |
| City GDP | ~AUD 605 billion (approx. USD 400 billion) |
| Per Capita Income | ~AUD 80,000 per year (approx. USD 53,000) |
| City Tier | Tier-1 |
| Key Strengths | Financial and business hub of Australia (headquarters for major banks, corporations) |
Companies Involved
| Header | Details |
|---|
| Developer / Operator | NEXTDC |
| Strategic Infrastructure Partner | NSW Govt (SSD Status) / TransGrid (330kV Interconnect). |
| Construction Contractor | Multiplex (Strategic ECI Partnership). |
| MEP Engineering | Fault-Tolerant; Prefabricated switchrooms; 330kV Direct-tie. |
| Network Connectivity | Diverse, high-capacity interconnects to the S1-S2-S3 cluster. |
| Power Infrastructure | 350 MW; Integrated 330kV high-voltage substation. |
Technical Specifications
| Header | Details |
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| Power Capacity | 350.0 MW |
| UPS Redundancy | Tier IV Fault-Tolerant (N+1 / 2N options for AI). |
| Cooling System | Advanced Air-Side with Rainwater Harvesting/Reuse. |
| Connectivity | Western Sydney anchor for global hyperscale and AI fabric. |
| PUE Target | < 1.15 (Targeted for AI-optimized tranches) |
| Energy Mix | Rooftop Solar PV, Low-carbon materials, EV Charging. |
Milestones
| Header | Details |
|---|
| Announcement | Construction Start: March 30, 2026; Ph 1 Ready: Mid-2027. |
| Construction Start | March 30, 2026 (Construction Commencement) |
| Phase 1 Go-Live | Mid-2027 |
| Full Buildout | 2030+ |
Investment Details
| Header | Details |
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| Total Investment | Multi-Billion Dollar Multi-Phase Buildout |
| Funding | NEXTDC A$1.3bn - A$2.2bn Capital Raising (2024-2026). |