Generator Installation Cost on Long Island: 2026 Pricing Guide

Turnkey, installed, permitted, inspected, and running:

• 14 kW air-cooled standby (partial house): $6,500 to $9,500
• 18-22 kW air-cooled standby (most whole houses): $9,800 to $13,500
• 24-26 kW air-cooled standby (larger homes with 200A service): $12,500 to $16,500
• 30-48 kW liquid-cooled (large homes, 2+ ACs, 400A service): $18,500 to $32,000

The sweet spot for a typical 2,500 sqft Long Island home with central AC, a couple of refrigerators, and some electronics is the 20-22 kW range at $10,500-$13,000 installed.

Anything quoted under $8,500 for a whole-house unit probably skips the gas plumbing, the permit, or the transfer switch interlock. Read the quote line by line.

Too-small is the most common mistake on Long Island. The generator will start fine but will not be able to hold all your loads through a 3-day Sandy-style outage. Here is how to size it honestly.

Essentials-only (partial house):

• Fridge, freezer, some lights, one window AC, internet, one gas furnace blower
• Target: 10-14 kW air-cooled. $6,500-$9,500 installed.

Whole-house, one AC:

• Everything essentials plus a single central AC up to 3 tons, electric oven, washer/dryer
• Target: 18-22 kW air-cooled. $9,800-$13,500 installed.

Whole-house, two ACs or heat pump:

• Two AC compressors, heat pump heat in winter, pool pump, hot tub, EV charger
• Target: 24-26 kW air-cooled. $12,500-$16,500 installed.

Estate-grade:

• Three ACs, full electric kitchen, elevator, pool + spa, car charging
• Target: 30-48 kW liquid-cooled. $18,500-$32,000 installed.

We do a load calculation on every quote that matches real nameplate amperage of your existing equipment against the generator's real-world continuous output. We do not guess.

Generator unit — 35-45% of total

The bare generator from a distributor, delivered to your driveway. A Generac 22 kW Guardian runs about $5,200 wholesale in 2026. A 24 kW Kohler 24RCL runs about $6,400.

Transfer switch — 8-12% of total

The automatic transfer switch (ATS) is the brain that senses the outage, starts the generator, and safely switches the house loads from PSEG power to generator power. A 200-amp service rated ATS runs $900-$1,400.

Gas plumbing — 12-18% of total

This is where a lot of quotes go wrong on Long Island. Natural gas pressure and flow from the utility is marginal for generator use. Most LI homes need:

• A dedicated 1-inch or 1.25-inch gas line from the meter to the generator (not a 3/4-inch tap off an existing dryer line)
• A pressure test documented for the gas inspector
• Sometimes a gas meter upgrade with National Grid — usually at no cost but requires a separate appointment

Gas plumbing on a typical install: $1,200-$2,200.

Electrical work — 15-20% of total

Running the generator output conductors from the unit to the ATS, bonding the ATS to the panel, adding a generator-emergency-stop, and updating grounding. $1,400-$2,400.

Concrete pad or composite pad — 2-4% of total

The generator needs to sit on a stable pad, 18 inches clear on all sides. Most installs use a composite pre-cast pad ($280) or a poured 4-inch concrete pad ($450-$650).

Permit and inspections — 4-6% of total

Two permits on Long Island: an electrical permit from the town for the ATS and circuit, and a gas/plumbing permit from the town or county for the new gas line. Inspections from NYBFU and the town plumbing inspector. $450-$750 total.

Labor — 15-20% of total

2-3 electricians and a gas plumber, 1-2 days on site depending on the run length and site conditions. $2,200-$3,500.

We install all three brands but we recommend Generac first to most Long Island customers. Here is why.

Generac is the market leader by a wide margin on LI. Parts availability from local distributors (Generac has a major distribution hub in Deer Park) is the best of any brand. If your unit ever needs warranty service, the turnaround is usually 3-5 business days. Generac Guardian units are reliable and the Mobile Link app works well. As a Generac PowerPro Elite Contractor, our warranty register goes through the factory directly.

Kohler is better-built and quieter (about 3 dB lower than comparable Generac). More expensive by 8-12%. Parts availability on LI is fine but not as immediate as Generac. Best for homeowners who will hear the generator run (close neighbors, small lots) or who want the premium option.

Briggs & Stratton is a budget option that was better 5 years ago than it is today. We have seen reliability issues on the current PowerProtect line. We generally steer homeowners away unless they have a specific reason.

Champion and other imports — we do not install them. Parts support is thin and the warranty claim process is painful.

About 85% of LI generator installs run on natural gas. About 15% run on propane, usually because:

• The home has no natural gas service (common in parts of the East End and Fire Island)
• The homeowner wants better cold-weather starting reliability (LP beats NG in extreme cold)
• The homeowner wants the fuel supply to be independent of the utility

LP adds $2,500-$5,500 to the install for the tank (leased or owned), the concrete pad, and the gas plumbing. Your propane company will deliver fuel on a scheduled basis.

Natural gas is simpler, cheaper upfront, and never runs out. For most LI homes, natural gas is the right call if you have it.

A standby generator needs annual maintenance to keep the warranty valid:

• Oil and filter change: every 100 hours of runtime or annually
• Air filter replacement: every 200 hours or every 2 years
• Spark plug inspection: every 200 hours
• Battery check: annually
• Exercise cycle verification: confirm the unit runs its scheduled self-test each week

We offer a $395/year maintenance plan on Long Island that covers all of the above plus priority service during outages. Most factory warranties require annual maintenance by an authorized dealer to stay in force — our plan checks that box.

DIY is an option but the warranty paper trail gets tricky. Most homeowners let a professional handle it.

A Long Island generator install requires:

1. Electrical permit from the town — $150-$350, 3-7 business days in Nassau, 5-12 in Suffolk
2. Gas/plumbing permit — $150-$300, sometimes combined with the electrical permit, sometimes separate
3. NYBFU or Commonwealth electrical inspection — $85-$185 after install
4. Town plumbing/gas inspection — $75-$150 after install
5. PSEG interlock notification — PSEG is notified via the ATS documentation; no separate fee but the transfer switch must be UL-listed and properly labeled

Skipping the permit is not worth the $600 you save. Homeowner's insurance will deny a claim on an unpermitted install if the generator ever causes property damage.

Unlike panel upgrades or heat pumps, standby generators do not qualify for most federal or state energy incentives because they consume (rather than save) fossil fuel.

However:

• Homeowner's insurance discount — some NY carriers offer a 2-5% premium discount for homes with standby generators. Check with your agent.
• Enhancify financing — 0% for 12-18 months on qualified borrowers, up to 15 years on longer terms. We run the application at the kitchen table and the approval takes 60 seconds.

• Walk-through: 45 minutes at your house. Confirm sizing, placement, gas route.
• Quote: in your inbox within 48 hours.
• Permit + PSEG notification: 5-14 business days depending on town.
• Generator arrives: 2-5 weeks from order to delivery (Generac has Deer Park in stock most of the year; Kohler can be 4-6 weeks).
• Install: 1-2 days on site.
• Inspections: within 1 week of completion.
• Warranty registration and first exercise cycle: we handle it.

Total typical timeline: 4-8 weeks from contract to fully running generator.

After Sandy in 2012 and Isaias in 2020, nobody on Long Island argues about whether a generator is worth having. The questions are which brand, how big, and will it be ready for the next one. The answer to the third one depends on how honest your installer is about sizing and gas plumbing.

We install Generac as our main line because the factory support on Long Island is unmatched. We install Kohler when the customer wants premium. We do the load calc, run the proper gas line, pull the permits, and back the install with a 3-year workmanship warranty on top of the factory warranty.

Get 3 quotes. Compare them line by line. Look at who pulls the permit, who runs the gas, and who you call at 2am during the outage.

Free generator sizing walk-through: Schedule here or call us direct.