T5 @ Chicago IV (Grayslake)

1.2 GW AI data center in Grayslake, IL, United States — under construction.

T5 @ Chicago IV (Grayslake) is a 1.2 GW AI data center project located in Grayslake, IL, United States, currently under construction. It is being built by T5 Data Centers. The estimated build cost is $18.0B. This project is one of thousands of data-center facilities tracked by Data Center Index across IL, United States — covering operational, under-construction, announced, and permitted sites.

Project description

T5 @ Chicago IV in Grayslake is approved and earthmoving has begun on the first phase; the campus is planned for 1.2 GW of IT capacity with phase 1 slated for 2027. An Aug 2026 report puts the phased build at up to $18B, 472 acres and 18 buildings, with early site work having begun in 2025 and a July 31, 2026 resident lawsuit seeking to halt it.

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