Chicago.

The market right now

This market has the widest equipment-age spread in the country: century-old building shells downtown running decades-old switchgear at high density, beside greenfield campuses that won't energize until 2031. Illinois has no statewide electrician license — Chicago and each suburb license separately — and private-sector enforcement is federal OSHA, not the state plan.

• ~1.9 GW IT load capacity in 2025, forecast 2.03 GW in 2026 across ~154 active facilities (Mordor Intelligence 2026)
• Colocation vacancy 1.9%, with no contiguous block of 5 MW+ available (CBRE H2 2025)
• Supply delivering through end of 2027 is over 90% preleased (CBRE H2 2025)
• Ranks 5th in North America for commissioned data center supply (datacenterHawk 2026)
• ComEd grid delays push some project energization to 2032+; development shifting to 500 MW+ sites with external power (CBRE H2 2025)

Every campus on the map

Solid copper markers are operating campuses; white markers are under construction; dashed outlines are announced or planned. Locations are approximate campus-level centroids compiled from public sources — county records, operator announcements, and market reports — as of August 2026. Dense clusters are grouped. Corrections are welcome through the contact page.

Operating campuses mapped

• 350 E Cermak carrier hotel — Digital Realty / Equinix · Downtown Chicago. 1.1M sq ft Lakeside Technology Center, one of the largest carrier hotels in the world; decades-old high-density electrical plant
• Elk Grove Village cluster — Digital Realty, Stack, Aligned, others · Elk Grove Village. Densest suburban colo cluster in the metro, adjacent to O'Hare; land near O'Hare essentially built out
• T5 Elk Grove portfolio — T5 Data Centers · Elk Grove Village. Five Elk Grove Village data centers after CHI V acquisition (T5 press release, Mar 2025)
• Prime Data Centers campus — Prime Data Centers · Elk Grove Village. Campus fully leased (CBRE H2 2025)
• CyrusOne Aurora I/II — CyrusOne · Aurora. Hosts CME Globex electronic trading platform — latency-critical financial ecosystem
• Edged Chicago ORD01-1 — Edged Energy · Aurora. 24 MW waterless-cooled facility operational Feb 2025 (Blackridge Research 2026)
• Meta DeKalb campus — Meta · DeKalb. $1B+ campus live Nov 2023 (State of Illinois 2023); expanded toward five buildings (Data Center Frontier)
• QTS Chicago — QTS · Chicago (near south side). Urban hyperscale-and-colo campus on South Ashland Ave

Under construction & planned

• PowerHouse Joliet — PowerHouse Data Centers / Hillwood · Joliet · planned. 1.8 GW campus with external power strategy (CBRE H2 2025)
• T5 Grayslake — T5 Data Centers · Grayslake · planned. 1.2 GW campus; 480 MW first phase targeted 2027 (Blackridge Research 2026)
• Equinix Minooka — Equinix · Minooka · planned. Equinix's first Illinois hyperscale campus, 300-acre site; construction ~2027, commissioning ~2031 (CBRE H2 2025; Blackridge 2026)
• CyrusOne CHI3 — CyrusOne · Aurora · under construction. Broke ground Sept 2024; 40 MW initial of 109 MW campus (Blackridge Research 2026)
• T5 CHI III — T5 Data Centers · Northlake · under construction. 36 MW; topped out May 2025, go-live 2027 (Blackridge Research 2026)
• Edged ORD01-2 — Edged Energy · Aurora · under construction. 72 MW; broke ground Nov 2025, expected Q2 2027 (Blackridge Research 2026)
• CyrusOne Wood Dale — CyrusOne · Wood Dale · under construction. New campus with first lease signed (CBRE H2 2025)
• Aligned ORD3 — Aligned Data Centers · Elk Grove Village · under construction. Anchor tenant secured (CBRE H2 2025)
• Microsoft Hoffman Estates — Microsoft · Hoffman Estates · under construction. Multi-building campus on former Sears land; $500M+ announced (Chicago Construction News; Baxtel lists buildings 1-4)
• DeKalb 560-acre proposal — Undisclosed developer · DeKalb · planned. 560-acre campus proposed Nov 2025 near Meta's site (Shaw Local 2025)
• Stream Elk Grove campus — Stream Data Centers · Elk Grove Village · planned. 2M+ sq ft three-building campus, ~10-year buildout (Data Center Frontier 2023)

Power

Service territory: ComEd (Exelon).

• ComEd requires 10-year letters of credit for 50 MW+ interconnections and quotes multi-year delivery timelines, some to 2032+ (CBRE H2 2025)
• Large-load queue pressure is pushing developers to 500 MW+ fringe sites with dedicated transmission, e.g. 1.8 GW Joliet campus (CBRE H2 2025)
• Rising PJM capacity costs and delivery delays are driving interest in on-site generation and BESS colocation at new campuses

The regulatory picture

Enforcement. Federal OSHA (Region V) covers private-sector work in Illinois; the Illinois OSHA state plan covers state and local government employees only

Licensing. No statewide electrician license in Illinois — licensing is municipal (e.g., City of Chicago supervising electrician registration), so qualification requirements vary by jurisdiction

Also in play. Illinois Data Center Investment Program grants ~20-year sales/use tax exemptions for $250M+ projects creating 20+ jobs (Illinois DCEO); used by DeKalb and suburban campuses

What it means for the work

The 70E conversation splits in two here. In the legacy stock, condition of maintenance under 110.3(C) is the whole ballgame — old gear, uncertain service records, real incident-energy consequences. On the greenfields, it's boundary control: keeping thousands of construction hands correctly classified as unqualified until they aren't.

Legacy carrier hotels (350 E Cermak) run decades-old switchgear at high density — condition of maintenance (70E 110.3(C)) directly drives incident energy

GW-scale greenfield builds in Joliet, Grayslake and DeKalb put thousands of construction electricians through the energization boundary from 1926 Subpart K into 70E territory

ComEd delays are pushing on-site generation and BESS colocation — new stored-energy, paralleling-gear and commissioning hazards

No statewide electrician license means qualified-person verification under 70E 110.4 falls entirely on the employer