The Joliet City Council has approved one of the largest proposed data center developments in the United States, clearing a major hurdle for the Joliet Technology Center, a $20 billion AI-driven campus planned southwest of Chicago.
The project is being led by PowerHouse Data Centers, alongside its parent company Hillwood. The council voted 8-1 to approve the annexation agreement for the 795-acre site, allowing the project to move into the next phase of planning.
Construction is expected to begin as early as 2027, with phased development continuing through 2032.
The Joliet Technology Center will consist of 24 two-storey data center buildings, delivering approximately 6.9 million square feet of built space.
The Energy Mag reports that the campus will be constructed in four phases, allowing infrastructure, utilities, and buildings to be developed in coordinated stages. At full buildout, the site is expected to reach a power demand of up to 1.8 gigawatts, placing it among the largest data center campuses in the region.
From a construction perspective, a campus of this size requires extensive coordination across site development, utility infrastructure, and building construction.
Developing a 795-acre site involves significant early-stage construction work before vertical building begins. Initial phases typically include:
Data center campuses also require high-capacity electrical infrastructure, including substations and distribution systems capable of supporting continuous operations.
Each of the 24 buildings will be designed as two-storey structures, optimized for housing servers, cooling systems, and supporting infrastructure.
Unlike traditional commercial buildings, data centers require specialized construction features such as:
The scale of this campus means these systems will be replicated across multiple buildings, requiring consistent design standards and phased construction sequencing.
The project will be built in four phases through 2032, allowing developers to align construction with infrastructure availability and tenant demand.
Phased construction enables:
This approach is critical for managing a project of this magnitude while maintaining schedule and cost control.
The construction phase is expected to generate between 7,000 and 10,000 jobs, making it one of the largest construction workforce mobilizations in the region.
Once operational, the campus is projected to support approximately 700 permanent jobs.
Large-scale infrastructure projects like this rely on a highly coordinated workforce across multiple disciplines, particularly during peak construction phases.
A data center campus of this size requires a wide range of specialized construction trades, including:
City officials highlighted the project’s long-term financial contributions, including an estimated $2.1 billion in tax revenue over 30 years. Additional revenue streams include $310 million in property taxes and utility-related income.
The development is also expected to drive infrastructure improvements tied to roads, utilities, and public services within the project area.
The approval follows weeks of public discussion and community input. A lengthy public hearing drew significant attention, with residents raising concerns related to:
Despite these concerns, the project received prior support from the Joliet Planning Commission and ultimately secured City Council approval.
With the annexation agreement approved, the project will now move into detailed planning, engineering, and permitting phases. These steps will include refining site plans, securing utility connections, and preparing for large-scale construction mobilization.
If timelines remain on track, construction could begin in early 2027, marking the start of a multi-year buildout.
The Joliet Technology Center represents a significant step forward in large-scale data center construction, driven by growing demand for artificial intelligence and cloud computing infrastructure.
As the project advances, it will stand as one of the most ambitious construction efforts in Illinois, combining extensive site development, complex building systems, and a multi-phase delivery strategy that will shape the region’s construction landscape for years to come.