Chicago Metro — Standby Generator Guide

Independent publication — not a contractor, not affiliated with any brand or installer.

What a standby generator costs in Chicagoland — and what size your home actually needs.

In August 2020, a derecho left about 58,000 DuPage County homes without power for up to five days — part of a storm that cut supply to more than 800,000 customers across northern Illinois — and a June 2021 EF-3 tornado tracked straight through Naperville. If you are thinking about a standby generator, you are thinking clearly.

Installed here, most homes land between $10,500 and $13,000 depending on size.

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Tell us about your home and a person reads it against installer coverage in your Chicago-area town. Where an installer covers you, your request goes to one of them and nobody else; where none does yet, we tell you so and you keep the cost, sizing and permit guidance. We are not a contractor and we never sell your request to a list.

The permit fee, the utility you deal with and the inspection sequence change at the municipal line. If you are in Naperville, Wheaton, Downers Grove or Aurora, start with that suburb's page: each carries the verified local permit fee, the utility rules that shape the install, and installed pricing in this labor market.

Typical installed cost in this region
14 kW
$10,500
18 kW
$11,900
22 kWmost common
$12,000
24 kW
$12,500
26 kW
$13,000

Installed, including a standard transfer switch. Permits, electrical upgrades and gas line work move the figure — what drives the number.

Why this publication exists

We are not a contractor. We are the neutral guide — real costs, verified permit fees, honest brand comparisons, and what your village requires. We are not a contractor and do not yet route requests to installers. Tell us about your home and we will tell you what the job should cost, what your village requires, and how to check an installer yourself.

Independent standby generator guidance for Chicago-area homeowners. Not affiliated with any brand or installer.

Find Your City

We help homeowners throughout the Chicago metro compare installer quotes and understand local permit requirements.

More Chicagoland suburb guides are in production.

Editorial Standards

Every figure on this site traces to a documented source, kept in a single evidence file and cited on the page. We grade each one by how strong that source is:

Verified primary source
Estimated · national range · MSRP-starting
Unconfirmed · disclosed gap

Figures are dated, and updated when they change. Where we can't confirm something from a primary source, we mark it as unconfirmed and say so rather than guess.

We are not a contractor, and we are not affiliated with any brand or installer.

Frequently Asked Questions

Do I need a permit in Naperville?

Yes. Naperville requires a generator permit plus a separate electrical permit. A licensed ICC electrician registered with the City of Naperville must pull the permits — homeowners cannot self-pull. The permit fee is $85 total ($40 permit + $45 inspection). Apply through the Civic Access portal at (630) 420-6100 Option 2.

How much does a 22kW generator cost installed in the Chicago area?

Starting at $12,000 for a standard Generac Guardian 22kW install from a Chicago-area dealer, permits excluded, assuming 10 feet of gas and electric piping. Complex installs — long gas runs, panel upgrades, difficult pad access — cost more. Generac's own installation FAQ cites an all-in national range of $8,000–$16,000; Chicago-area labor sits toward the upper end of that range.

Generac or Kohler — which is better?

For most Naperville homeowners, either works. Generac has a much larger local installer network and a lower equipment MSRP — a 26kW Guardian starts at $6,989 vs. Kohler's 26RCA at $7,445 (both starting figures; final dealer-set pricing varies). Kohler is reported by industry sources to use cast iron engine blocks and publishes a notably quieter exercise-cycle figure; normal-load ratings are the same 67 dB(A). Generac has an active class action covering alleged alternator defects in 22kW and 24kW units — check your serial number against the class definition at classaction.org before buying. See our full comparison for the complete breakdown.

Is 14kW enough for my 2,500 sq ft home?

Probably not if your home has a 4-ton AC and you want whole-home backup. Generac's published spec rates the 14kW Guardian at 14kW on natural gas — no fuel derating. The issue is raw load headroom: a 4-ton AC compressor draws up to 8,500W at startup (its published starting surge, per manufacturer compressor specs); add a furnace blower (~800W running) and a refrigerator (~700W), and you approach 10,000W in concurrent demand — leaving only ~4kW of headroom on a 14kW unit. One additional appliance cycling at startup and you are at the limit. 22kW is the answer for most DuPage County homes.

Does my HOA need to approve the installation?

HOA covenants (CC&Rs) operate independently of city permits. A city permit doesn't override private HOA rules. Check your CC&Rs before ordering equipment — some HOAs require board approval, screening, or specific placement.

Does Naperville Electric or ComEd serve my home?

Most Naperville addresses use the City of Naperville's municipal electric utility, not ComEd. Check your bill — it will say either 'City of Naperville' or 'ComEd.' It matters in an outage: Naperville's own Department of Public Utilities lists (630) 420-6060 as the number to report an electrical outage, so reporting to ComEd would reach the wrong utility. Naperville Electric also requires a transfer switch and an exterior service disconnect on every generator installation, which the City cites to NEC 701-7 and 702-6.

How long does the whole process take?

From permit application to commissioning: typically 4–8 weeks if Nicor Gas meter work is needed (allow ~3–4 weeks for that alone). If your existing gas service has sufficient capacity and site conditions are straightforward, 2–3 weeks is realistic.

Does natural gas reduce a generator's output?

For current Generac Guardian models, the NG/LP difference is small: the 14kW Guardian is rated at 14kW on both fuels per Generac's published spec; the 22kW rates at 21kW on NG vs 22kW on LP. The reason to choose 22kW for a 4-ton AC home isn't fuel derating — it's raw load headroom. A 4-ton AC compressor draws up to 8,500W at startup (per manufacturer compressor specs); add a furnace blower and refrigerator cycling and you approach 14kW's limit quickly. The 22kW at 21kW on NG gives you comfortable margin.

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