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DuPage County, IL Building Safety: Electrical Permits (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Code adopted
NFPA 70-2020, NEC, Sec. 8-600
Romex/NM cable
Not adopted, Article 334 deleted
Conductor material
Copper only, aluminum barred
1-2 family service size
200 amps, 3-wire minimum
Permit required
Sec. 8-112.1, before work starts
Violation fine
$100-$1,000 per day, Sec. 8-117.4

Summary

Unincorporated DuPage County runs on the 2020 National Electrical Code under Sec. 8-600, but with local teeth: standard Romex sheathed cable and armored cable are not adopted, all conductors must be copper, and one- and two-family homes need a 200-amp, three-wire service.

City-specific rules exist: Naperville has its own electrical permits rules that differ from DuPage County's county-level regulations. If you live in Naperville, check the city-specific page instead.

There is hereby adopted by reference, as if fully set out herein, that certain code known as The National Electrical Code, 2020 edition, (NFPA 70-2020) as sponsored and published by the National Fire Protection Association, together with the following additions, insertions, deletions and amendments hereinafter set forth. ... Any reference in said code to the "authority having jurisdiction" shall mean the Building Official of the County of DuPage, Illinois. ... 230.79(C) One Family Dwelling. For a one and two-family dwelling, the service disconnection means shall have a rating of not less than 200-amperes, three (3) wire and be located on the principle structure, one (1) service per dwelling unit, unless otherwise approved by the Building Official.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 14 Update 1).

Full Breakdown

Sec. 8-600 adopts NFPA 70-2020 by reference and makes the DuPage County Building Official the "authority having jurisdiction" for every provision in it. The County then strips out seventeen wiring-method articles outright, including Article 334 Nonmetallic-Sheathed Cable (standard residential Romex), Article 330 Metal-Clad Cable, Article 320 Armored Cable and Article 338 Service-Entrance Cable, so wiring that is code-legal almost everywhere else in the country cannot be used here. 2(B) go further and delete every reference to non-copper conductors, meaning aluminum wiring is not permitted at all.

On the service side, amended Sec. 79(C) requires a one- or two-family dwelling's service disconnect to be rated at least 200 amperes, three-wire, located on the principal structure, with one service per dwelling unit unless the Building Official approves otherwise. 10(D)(1)). Electrical work itself needs a permit under Sec. 1 before it starts, and inspections (rough electric, under-slab electrical, and final electrical service energization) are scheduled per the Building Division's inspection list.

Violations & Fines

Unpermitted or noncompliant electrical work draws a Notice of Violation under Sec. 8-117.2, giving the owner 14 days to pay a $100 inspection fee and get the permit corrected or the wiring brought into compliance, with a right to appeal to a Hearing Officer within that same window. If it isn't cured, Sec. 8-117.4 sets a fine of $100 to $1,000, with every additional day of noncompliance treated as a separate offense, and the Building Official can also issue a stop-work order under Sec. 8-118.1 that halts work immediately.

Frequently Asked Questions

Does DuPage County allow standard Romex wiring in unincorporated areas?
No. Sec. 8-600(B)(1) specifically lists Article 334, Nonmetallic-Sheathed Cable Types NM, NMC and NMS, among the NEC articles the County has not adopted, along with armored cable, metal-clad cable and several other cable types. Contractors need to use adopted raceway or cable methods instead.
Can I use aluminum wire for an electrical remodel in DuPage County?
No. The County's amendment to NEC Section 310, covering conductors for general wiring, states that conductors "shall be of copper only" and deems all other references to conductors, including aluminum, deleted from the code. Only copper conductors are permitted.
What size electrical service does a new DuPage County home need?
Amended Section 230.79(C) requires a one- or two-family dwelling's service disconnecting means to be rated at least 200 amperes, three-wire, and located on the principal structure, with one service allowed per dwelling unit unless the Building Official approves an exception.
Do I need a permit for electrical work in unincorporated DuPage County?
Yes. Sec. 8-112.1 makes it unlawful to install equipment or wiring covered by the Building Code without first filing a written application and getting a formal permit from the Building Official, and inspections are required at rough-in and before the service is energized.

Sources & Official References

Other rules in DuPage County

All DuPage County rules

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