Reading Your Generator Quote
A generator installation quote can feel overwhelming if you do not know what you are looking at. Reputable installers break down every cost so you can see exactly where your money goes. If an installer gives you a single lump-sum number with no detail, ask for an itemized breakdown — or find a different installer.
Here is what each line item means and what it should cost.
The Generator Unit
This is the most expensive single item, typically 40–50% of the total project cost. The price depends on the size (kW rating), brand, and fuel type.
Air-cooled generators (10–26 kW): $3,000–$6,500 for the unit alone. These are the most common residential models. They use ambient air for cooling and are suitable for most homes.
Liquid-cooled generators (25–48+ kW): $6,000–$15,000+. These use an engine coolant system similar to a car and are designed for large homes or commercial applications. They run more quietly and handle sustained heavy loads better.
The unit price usually includes the base warranty (typically 5 years) and the weather-resistant enclosure.
Automatic Transfer Switch (ATS)
The transfer switch is the second most critical component. It monitors utility power and automatically starts the generator when an outage is detected.
Whole-house ATS (200 amp): $800–$1,500. This type handles your entire electrical panel. Load-center ATS (100–150 amp): $500–$900. This manages selected essential circuits.
Some premium ATSs include power management features that can prioritize loads and shed non-critical circuits when the generator approaches capacity. These cost $200–$400 more but allow a smaller generator to cover more circuits.
Site Preparation
Concrete pad: $200–$500. The generator sits on a level pad at least 4 inches thick. Some installers use pre-cast composite pads that cost slightly more but install faster.
Gravel bed: $75–$200. Required under and around the pad for drainage in some jurisdictions.
Clearance work: $0–$500. The generator must be placed a certain distance from windows, doors, and property lines (typically 5 feet from openings, 18 inches from the house). If bushes, fencing, or other obstacles need to be moved, this adds to the cost.
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Electrical Work
This is where costs vary the most based on your home’s existing electrical setup.
Transfer switch installation: $400–$800 in labor. The ATS is wired into your main electrical panel, which involves shutting off power and carefully connecting the new circuits.
Wiring run from generator to panel: $300–$800. The distance between the generator and your electrical panel affects the amount of conduit and wire needed. Longer runs cost more.
Panel upgrade: $1,500–$3,500 if needed. If your panel is older than 25 years, uses Federal Pacific or Zinsco breakers, or does not have sufficient space for the transfer switch, a full panel upgrade is required. This is common in older homes and is a non-negotiable safety requirement.
Gas Line Work
Natural gas connection: $300–$800. This involves running a gas line from your existing gas meter to the generator location. The gas utility may need to upgrade your meter at no charge if it cannot handle the additional load.
Propane line and tank: $2,000–$4,000 total. This includes a 250–500 gallon above-ground tank ($1,500–$2,500), gas line from tank to generator ($300–$800), and the initial propane fill ($300–$600).
Underground propane tank: Add $1,000–$2,000 for excavation and burial. Underground tanks are required by some HOAs and preferred by homeowners who want to keep their yard clear.
Permits and Inspections
Electrical permit: $75–$300. Required in virtually all jurisdictions.
Gas/plumbing permit: $50–$200. Required when running new gas lines.
Final inspection: Usually included in the permit fee. An inspector verifies that all work meets code before the system is activated.
Your installer should pull all permits and schedule inspections as part of the project. If an installer suggests skipping permits, walk away — unpermitted work can void your warranty, violate your homeowners insurance, and create serious safety hazards.
Labor Costs
Standard installation (1–2 days): $1,500–$3,000. This covers a two-person crew for site prep, equipment placement, electrical work, gas line connection, testing, and homeowner walkthrough.
Complex installation: $3,000–$5,000+. Difficult site access, extensive panel work, long gas runs, or unusual configurations add time and labor.
Putting It All Together
For a typical 20 kW natural gas installation at an average home, the total breaks down roughly like this:
- •Generator unit: $4,500
- •Transfer switch: $1,000
- •Concrete pad: $300
- •Electrical work: $1,500
- •Gas line: $500
- •Permits: $200
- •Labor: $2,000
- •Total: $10,000
This is a representative example. Your actual cost will depend on your specific situation, which is why an on-site quote is the only way to get an accurate number.
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GeneratorPrice Editorial Team
Our editorial team researches and writes every article with input from licensed generator installers, electricians, and industry professionals. We are committed to providing accurate, unbiased information to help homeowners make informed decisions about backup power.