A permanent standby generator is a significant electrical installation that almost always requires a permit. The threshold isn't size alone — it's the combination of fuel type, generator capacity, whether you're adding an automatic transfer switch, and the specific electrical and structural modifications your installation demands. Portable generators you roll out during a power outage are different; this guide covers permanently installed units that integrate with your home's electrical panel and gas or propane supply. Most jurisdictions require both an electrical subpermit (handled by a licensed electrician) and a building permit (for the foundation, fuel-tank placement, and enclosure). The National Electrical Code (NEC 700 and 750, which govern standby and backup power systems) sets the national floor, but your state building code and local amendments determine whether your specific project needs plan review, inspections, or both. The key is determining whether your generator crosses the threshold in your jurisdiction — and if it does, whether you're filing the right permit type.
When standby generators require permits
A permanently installed standby generator triggers a permit in nearly every jurisdiction. The only exceptions are rare: a replacement generator of identical capacity and fuel type in the exact same location might be exempt under like-for-like replacement rules in some jurisdictions, but this is uncommon and must be confirmed with your building department before work starts. If you're adding a new generator, upgrading an existing unit, changing fuel type, increasing capacity, or installing a transfer switch for the first time, you need a permit. The NEC requires that any generator connected to building wiring (rather than used as a portable temporary source) comply with NEC Article 700 (emergency systems) or Article 750 (standby systems), and that requires permitting.
Generator size is the first decision point. The NEC doesn't set a blanket capacity threshold, but most jurisdictions do. A 5 kW portable unit that you wheel out for camping or a weekend away is not a standby generator in the permitting sense. A 7 kW unit that's permanently mounted on a concrete pad, wired to an automatic transfer switch, and connected to your electrical panel is. Many jurisdictions set the threshold at 10 kW or higher for residential generators — anything smaller can sometimes be installed without a permit, but only if it's not connected to an automatic transfer switch. If it has a transfer switch, it needs a permit regardless of size, because the switch itself is a complex piece of electrical apparatus that integrates with your main panel and requires inspection.
Fuel type matters because it determines whether you need additional permits beyond electrical. A natural-gas generator requires coordination with your gas utility and may trigger a mechanical permit if your jurisdiction has one. A propane generator requires a propane-tank permit and fuel-storage safety inspection. A diesel unit carries different fuel-storage and environmental rules. Gasoline generators are rare for permanent installations and come with fire-code implications. Your local authority having jurisdiction (AHJ) — usually the building department but sometimes the fire marshal — will flag these issues. A 15 kW natural-gas unit might need only an electrical permit plus a minor gas-line permit. A 20 kW propane unit with a 500-gallon tank might need building, electrical, mechanical, and fuel-storage permits. Call your building department first and ask which permits your specific fuel choice requires.
The automatic transfer switch is the most common permit trigger. An ATS detects a utility outage, starts the generator, and switches your home's load from grid power to generator power. The NEC treats an ATS as part of the standby power system and requires it to be listed, installed to code, and inspected. This means even a smaller generator — say, 8 kW — needs a permit if it has an ATS. Without an ATS, you're operating a generator manually, which means you manually connect a load-interlock device or manually disconnect from the grid before plugging in the generator. Most modern installations include an ATS because manual transfer is risky (you can backfeed the utility and electrocute a lineman), so most residential standby generators require a permit.
The structural and site-work scope determines whether you need a building permit in addition to electrical. A generator mounted on a concrete pad that didn't exist before requires a building permit for the foundation — your frost depth, soil conditions, and local frost-line requirements all matter. In Wisconsin, frost depth is 48 inches; a pad can't be poured on-grade. In Florida, frost depth is zero and pad requirements are minimal, but hurricane tie-downs and corrosion-resistant foundations matter. You need to grade the site for drainage, ensure the unit sits away from windows and doors (per NEC and building code), and make sure fuel-tank placement complies with setback rules. If your installation is just swapping an old generator pad for a new one in the same footprint, you might not need a building permit — but check with the building department. If you're placing a generator for the first time or in a new location, you almost certainly do.
Check with your local building department before ordering a unit or scheduling installation. A 90-second phone call — describe your fuel type, intended capacity, whether you want an ATS, and where you plan to locate the unit — will tell you exactly which permits you need. Many jurisdictions process generator permits quickly (2–3 weeks) because they're straightforward applications. Some offer expedited or over-the-counter permits for standard residential generators. Others require a full plan review if the installation is complex or the property has site constraints. Knowing this upfront saves you from the common mistake of ordering a unit, having an electrician show up, and then discovering your building department requires a permit that's now delaying work.
How standby generator permits vary by state
The NEC is adopted nationwide with state amendments, so the baseline code is consistent. However, states add their own requirements. Florida requires generators in hurricane-zone residential construction to meet the 2023 Florida Building Code, which mandates impact-resistant foundations, corrosion-resistant materials for coastal properties, and tie-downs for wind loads. A 20 kW generator in Miami requires more foundation work than the same unit in inland Florida. California enforces strict interconnection rules if your generator is also paired with a battery or solar system; California Title 24 energy code requires certain efficiency standards and documentation. A Texas jurisdiction might have minimal foundation requirements but strict fuel-tank setback rules if the property is in a floodplain or near a water supply.
State electrical boards also vary. Some states require the electrical subpermit to be pulled by a licensed electrician only; others allow homeowners to pull it if they meet training or exam requirements. New York, Massachusetts, and several Northeast states have rigorous electrical inspection standards and longer plan-review timelines (3–4 weeks). Western states like Arizona and Colorado often streamline generator permits if the unit is under a certain size. Texas and Florida expedite permits for residential generators under 20 kW, often processing them over-the-counter in 1–2 weeks. Midwest states like Wisconsin and Minnesota follow the IRC closely with state amendments but generally don't add major generator-specific rules, so timelines are predictable (2–3 weeks).
Fuel-supply coordination also varies. Natural-gas generators in states with municipal gas utilities (California, Illinois, New York) often require the utility to inspect the gas line and approve the generator's gas demand. In rural areas served by propane suppliers, the supplier may need to approve the tank location and fuel-supply line before the building department will issue a permit. Some states require an environmental assessment if the generator is larger than a threshold (usually 50 kW residential, rarely encountered) or if the property is in a sensitive area. Most residential generators don't trigger environmental review, but it's worth asking if your property is in a wetland, floodplain, or protected zone.
Common scenarios
Installing a 12 kW natural-gas standby generator with automatic transfer switch
This is the most common residential scenario and requires a permit. The 12 kW capacity, automatic transfer switch, and natural-gas fuel all cross the threshold. You need an electrical permit for the ATS, generator wiring, and integration with your main panel (NEC 700 and 750 compliance). You need a building permit for the concrete pad foundation (which must meet local frost-depth requirements), drainage, setbacks from windows and doors, and gas-line modifications. Your electrician pulls the electrical permit and coordinates with a licensed gas fitter (who may need a separate trade license in your state). The building department issues the building permit, and both permits require inspections — typically a foundation inspection before the pad is poured, an electrical rough-in inspection before drywall or finish work, and a final inspection after everything is running. Expect 3–4 weeks for plan review and permitting, plus 1–2 weeks for inspections depending on the season. Cost is typically $200–$400 for permits plus any plan-review or engineering fees if the building department requires them.
Replacing an existing 10 kW propane generator with an identical new unit in the same location
This is the gray zone. If the old generator's foundation and fuel tank are still in place and the new unit is the same capacity and fuel type, some jurisdictions allow this as like-for-like replacement and exempt it from permitting. However, this is rare and must be confirmed with your building department. Most jurisdictions require a permit even for replacement because the new generator will be integrated with a new electrical system (new wiring, new ATS, new integration with your main panel), which triggers an electrical permit. The building department may then pull in a building permit requirement for the foundation inspection, especially if the old pad is deteriorating or needs replacement. The safest approach is to call your building department and describe the project exactly: old generator model, new generator model, existing pad condition, existing fuel tank condition. If they confirm no permit is needed, get it in writing (even email confirmation counts). More likely, they'll require at least an electrical permit. Budget 1–2 weeks and $100–$250 for permits if required.
Installing a 7 kW portable-style generator on a permanent pad with manual transfer (no automatic switch)
No permit required in most jurisdictions. A 7 kW generator without an automatic transfer switch is below the capacity threshold in many areas, and the absence of an ATS means it's not integrated into your home's electrical system — you're using it as a temporary backup power source that you manually connect with a portable cord or load-interlock switch. The fact that it has a permanent pad doesn't change this, as long as the pad is at-grade and doesn't require deep footings (check your local frost-depth rules). However, confirm this with your building department, because some jurisdictions set the threshold lower (5 kW or 10 kW), and some treat any permanently mounted unit with a transfer device as requiring a permit. The manual-transfer approach is risky — you must manually disconnect from the grid or use an interlock device to prevent backfeeding — so it's not recommended, but it is exempt from permitting in many jurisdictions. If you later decide to add an automatic transfer switch, you'll need a permit at that point.
Installing a 25 kW diesel standby generator for a residential property in a flood zone
This requires permits and additional site review. The 25 kW capacity alone triggers a permit. Diesel fuel and a unit of this size require a mechanical or fuel-storage permit in addition to electrical and building permits. Placement in a flood zone likely triggers a Flood Plain Development Permit or a variance because FEMA and state floodplain rules typically prohibit new mechanical equipment and fuel storage in flood zones unless it's elevated above the base flood elevation or protected by a levee. You'll need a survey showing the property's elevation relative to the 100-year flood elevation, and the generator pad must be rated for elevation or flood-resistant placement. Your local floodplain administrator (usually in the planning or public works department, not the building department) must sign off before the building department will issue a building permit. This adds 4–8 weeks to the timeline because the floodplain permit is often sequential — you can't pull building permits until you have floodplain approval. Costs rise to $400–$800+ because of engineering and survey requirements, plus separate flood-zone and mechanical permits.
Installing a 6 kW natural-gas generator hardwired to the electrical panel with automatic transfer switch
Permit required. Even though 6 kW is on the smaller end, the automatic transfer switch is the trigger. An ATS is a listed electrical device that integrates your generator with your main electrical panel and requires an inspection to verify it's installed to code (NEC Article 700 or 750). You need an electrical permit for the ATS, generator wiring, and integration. You also need a building permit for the concrete pad (unless your building department confirms the pad can be poured at-grade without a footing inspection — unlikely in cold climates). The gas-supply line may require a separate gas-permit or may be bundled into the electrical permit depending on your jurisdiction. Most building departments process this within 2–3 weeks. Cost is typically $150–$300 for permits.
What documents to file and who should pull the permits
| Document | What it is | Where to get it |
|---|---|---|
| Electrical Permit Application | The primary permit for the standby generator. Includes the generator's model, capacity, fuel type, ATS details, main-panel integration, and wiring diagram. The NEC sections cited are typically 700.3 (general requirements for emergency systems) or 750.4 (general requirements for standby systems). | Your local building department — ask which form they use (many jurisdictions have a single electrical-permit form that covers generators). Some departments have online portals where you can download and pre-fill the form; others require in-person filing. |
| Building Permit Application (if required) | Covers the generator pad foundation, site drainage, setbacks from openings, and overall placement on the property. Required if you're pouring a new pad or if local code requires a building permit for any generator installation. Some jurisdictions bundle the building permit with the electrical permit; others require separate filing. | Your local building department. The application will ask for lot size, generator location, distance from the house and property lines, and foundation design (depth, footing requirements based on frost depth). |
| Site Plan or Sketch | A drawing showing the property, house location, property lines, the proposed generator location with dimensions, setbacks from windows and doors, fuel-tank location (if applicable), and existing utilities. Doesn't need to be to scale or professionally drawn, but must be clear and dimensioned. This is the single most-common item missing from permit applications. | You prepare this. A simple sketch on graph paper is usually sufficient for residential generators. If the installation is complex (tight site, floodplain, tight setback to a property line), ask the building department if they want a professional survey. |
| Generator Specification Sheet | The manufacturer's data sheet for the generator unit you're installing. Includes model, capacity (kW), fuel type, voltage, ATS compatibility, and any special installation requirements. Most manufacturers provide this as a PDF; you download it from the manufacturer's website using the model number. | The generator manufacturer's website or your supplier. Print or PDF it and attach to your permit application. |
| Single-Line Diagram (Electrical Wiring Plan) | A diagram showing how the generator connects to your main electrical panel, the ATS, and the rest of the home's electrical system. Shows the generator disconnect switch, ATS, main panel location, and major branch circuits served by the generator. A licensed electrician typically prepares this; it doesn't need to be a full architectural drawing but must show the electrical path clearly. | Your licensed electrician prepares this as part of the permit application. If you're submitting the permit yourself (rare for residential generators), ask the building department if a simple sketch is acceptable or if they require a professional diagram. |
| Propane or Gas-Supply Plan (if applicable) | A drawing or written description of the gas or propane supply line from the utility meter or tank to the generator. Shows the line route, materials, and connection points. May be required separately by the gas utility or the building department. | Your gas fitter or HVAC contractor prepares this. The gas utility (if it's natural gas) may require it as part of their approval process. For propane, the propane supplier often provides tank placement approval and will require a distance diagram showing the tank location relative to the building and property lines. |
| Affidavit or Floodplain Certification (if applicable) | If the property is in a mapped flood zone, you may need to certify the generator's elevation relative to the base flood elevation, or obtain a floodplain development permit. This is typically a form from the local floodplain administrator (often in planning or public works, not building). | Your local floodplain administrator or planning department. Ask your building department if floodplain approval is required before they'll issue a building permit. |
Who can pull: A licensed electrician almost always pulls the electrical permit for a standby generator. Some jurisdictions allow homeowners to pull the electrical permit if they meet state licensing requirements (rare in most states), but the generator installation and ATS integration are complex enough that hiring a licensed electrician is strongly advised — they understand the NEC requirements, know what the local AHJ expects, and can speak to the inspector if issues come up. The building permit is often pulled by the homeowner or the electrician, but if the site work is complex (tight setbacks, floodplain, significant grading), a general contractor or engineer may need to coordinate. If you're pulling the permit yourself, the building department can tell you what's missing before you file — take advantage of the 5–10 minute pre-filing consultation to avoid a rejection.
Why standby generator permits get rejected
- Site plan or sketch is missing or too vague.
Draw a simple sketch showing your property, house location, property lines, and the proposed generator location with dimensions. Mark the setback distances from windows, doors, and property lines. Show where the fuel tank (if any) will sit. This is the most-common rejection — the building department needs to verify that the unit is placed safely and legally on your property. - Generator capacity or fuel type is listed incorrectly, or model number doesn't match the actual unit being installed.
Double-check your generator spec sheet. The model number, capacity (kW), and fuel type must match exactly. If you change units mid-project, file an amendment or resubmit with the correct model and capacity. Inspectors verify this during final inspection, and mismatches can delay sign-off. - Automatic transfer switch is not shown or ATS compatibility with the main panel is not documented.
If you're installing an ATS, include the ATS model and a one-line electrical diagram showing how it connects to the main panel. The ATS must be listed (appear on an NEC-approved list) and be compatible with your panel. Your electrician can confirm this; it's not optional. If you're not installing an ATS, document the manual-transfer method (load interlock, portable cord, etc.) — though this is rarer and requires building-department approval. - No written confirmation of gas-utility approval or propane-supplier approval.
Contact your gas utility (for natural gas) or propane supplier before filing. Ask for written approval or a requirement letter stating the fuel-supply line specs they need. Include this with your application or submit it when the building department asks. The utility or supplier must inspect the gas or propane line before the generator can be put into service anyway. - Building permit is required but not filed — only electrical permit is submitted.
Call your building department and ask explicitly: Do I need a building permit for a standby generator? Most jurisdictions require one, but some bundle it with the electrical permit or don't require it if you're replacing a like-for-like unit on an existing pad. Get a clear answer and file the building permit at the same time as the electrical permit. Filing both at once speeds up processing. - Setback from windows, doors, or property lines is inadequate or not shown.
NEC and local building codes typically require a minimum distance from operable windows and doors (often 3–5 feet, depending on the jurisdiction). Check your local ordinance. Measure from the generator's exhaust to the nearest window or door, and show this on your site plan. Propane or natural-gas supply lines also have minimum setback requirements from buildings; verify these with your gas utility. - Foundation depth or frost-footing detail is missing or doesn't meet local frost-depth requirements.
Every jurisdiction has a minimum frost depth. A Wisconsin generator pad must have footings below 48 inches; a Florida pad typically doesn't. Ask your building department for the frost-depth requirement and include a footing detail showing that the pad meets it. If you're pouring a pad shallower than the frost depth, you'll need a variance or a design engineer's letter explaining why frost-depth isn't applicable (rare).
Standby generator permit costs and typical fees
Permit fees for standby generators are typically flat fees or calculated as a percentage of project valuation. Most jurisdictions set a flat fee because generators are standard residential installations. The electrical permit is usually separate from the building permit, so you may pay two separate fees. Plan-review fees, if charged separately, run $50–$150 depending on whether the building department considers the project routine or complex. Inspection fees are bundled into most residential permits. If the building department requires engineering review (for floodplain work, site constraints, or non-standard installations), add $200–$500 for a plan-review engineer. Labor costs for the electrician and any site work are separate from permit fees — plan on $2,000–$6,000 for a typical 12–20 kW installation with ATS, depending on the distance from the panel and site conditions.
| Line item | Amount | Notes |
|---|---|---|
| Electrical permit (residential generator, standard installation) | $50–$200 | Most jurisdictions charge a flat fee. Some use 1.5–2% of project valuation (contract price for labor and materials); others have a fixed scale by capacity. |
| Building permit (pad, site work, structural components) | $75–$250 | Bundled with electrical permit in some jurisdictions; separate in others. Not required in a few jurisdictions if the generator is a like-for-like replacement. |
| Gas or propane utility permit/inspection coordination | $0–$100 | Often included in the utility's service cost, not a separate permit fee. Contact your gas utility or propane supplier — they may charge a line-inspection fee or include it in the service connection. |
| Floodplain permit (if property is in flood zone) | $100–$300 | Separate from building and electrical permits. Required if the property is in a mapped flood zone and the building department or floodplain administrator requires it. |
| Plan-review fee (complex site, engineering required) | $100–$500 | Charged only if the building department orders plan review beyond standard inspection. Tight setbacks, non-standard foundation, floodplain, or lot constraints may trigger this. |
| Inspection fees (foundation, electrical rough-in, final) | Included in permit fees | Most jurisdictions bundle inspections into the permit fee. A few charge per-inspection; typical cost is $50–$75 per inspection if charged separately. Expect 2–4 inspections depending on scope. |
| Total permit cost range (typical residential installation) | $200–$600 | For a standard 12–20 kW natural-gas or propane generator with pad and ATS in a non-floodplain location. Adds $150–$300 if floodplain, tight setback, or engineering review is required. Does not include labor, materials, or electrician fees. |
Common questions
Do I need a permit if I'm replacing my old generator with a new one of the same size?
Almost always yes, even if the unit is the same capacity and fuel type. The new generator will have new wiring, a new connection to your main panel, and possibly a new or updated ATS, which triggers an electrical permit. If the old pad and fuel tank are being reused and are in good condition, you might not need a building permit in some jurisdictions, but you'll definitely need an electrical permit. A small number of jurisdictions treat old-to-new replacement as like-for-like and exempt it, but this is rare. Call your building department and describe the project — they'll tell you which permits you need. Get the answer in writing if possible.
What's the difference between an automatic transfer switch and a manual transfer switch?
An ATS detects a utility outage automatically, starts the generator, and switches your home's electrical load from the grid to the generator — all without you doing anything. A manual transfer switch requires you to manually flip a switch or physically disconnect the generator from the grid before starting it. Manual transfer is cheaper upfront but risky: if you forget to disconnect, you can backfeed the utility and kill a power-line worker. The NEC allows manual transfer in emergency situations, but most modern residential generators use an ATS for safety. An ATS almost always requires a permit because it's a complex electrical device integrated with your main panel. A manual-transfer-only setup might not require a permit in some jurisdictions, but it's not recommended and you should check with the building department before going this route.
How long does it take to get a standby generator permit?
Most residential generator permits process in 2–4 weeks from filing to approval, depending on the jurisdiction and whether plan review is required. Some building departments offer over-the-counter permits for standard residential generators — you walk in, file the application with all documents, and walk out approved in an hour. Others require a formal 2–3 week plan review. If the property is in a flood zone or has site constraints, add 4–8 weeks for floodplain review or engineering. Once approved, inspections typically happen within 1–2 weeks of your request. The entire process from filing to final inspection sign-off is usually 4–6 weeks for a straightforward installation. Call your building department and ask: Is generator permitting routine or complex in your jurisdiction? That'll give you a realistic timeline.
Can I install a standby generator myself, or do I need a licensed electrician?
You can pull the permit yourself in most jurisdictions, but the actual installation must be done by a licensed electrician in virtually every state. The NEC requires that standby-power systems (generators with ATS) be designed and installed per code, and the inspector will expect to see professional work. Even if your state allows owner-builders to wire their own homes, standby generators are usually an exception because they're interconnected systems that affect utility safety (backfeeding). Hire a licensed electrician. They'll pull the electrical permit, order the materials, do the installation, and coordinate inspections. You can handle the building permit for the pad if that's separate, but the electrical side is the electrician's domain.
What happens if I install a standby generator without a permit?
The generator will work, but you're taking on significant risk. The building department can order you to stop work, remove the unit, and redo the installation to code — at your cost. If the property is sold, the unpermitted installation can delay the sale or lower the property value. If the generator causes an electrical fire or a utility-backfeeding incident, your insurance may deny a claim if the work wasn't permitted. The NEC and local fire code exist for safety — an unpermitted installation that injures someone or damages property puts you in legal liability. Inspectors occasionally find unpermitted generators during routine maintenance inspections or when reviewing a property record. The permit cost ($200–$600) and timeline (4–6 weeks) are small compared to the risk. Get the permit.
Do I need a propane-tank permit if I'm installing a propane generator?
Yes, in most jurisdictions. A propane tank serving a generator is an above-ground storage tank, and it requires a permit or approval from the building department or fire marshal. The tank size, location, setbacks from the building and property lines, and ventilation all matter. Your propane supplier will have specific requirements (the tank typically must be 10 feet from windows or doors, 5 feet from the building foundation, and outside any flood zone). The building department will require these details on your site plan. File the building permit at the same time as the electrical permit and include the propane-tank placement and setbacks. The propane supplier will also inspect the tank installation before they'll deliver fuel, so coordinate with them early.
What's the frost-depth requirement, and why does it matter for a generator pad?
Frost depth is how deep the ground freezes in winter in your area. In cold climates (Wisconsin, Minnesota, upstate New York), frost depth is 36–48 inches or deeper. In warm climates (Florida, Southern California), frost depth is zero or a few inches. Building codes require that foundations and structural footings go below the frost line to prevent frost heave, where the soil expands as it freezes and pushes the structure upward, cracking the pad or misaligning equipment. A generator pad's footings must extend below the local frost depth. If you don't go deep enough, the pad can heave and crack, damaging the generator and its gas line. Your building department will specify the frost depth in the building code or in the permit checklist. Ask when you call to confirm permit requirements.
Can I install a generator next to my house, or does it need to be far away?
A generator must maintain minimum setbacks from operable windows, doors, and air intakes — typically 3–5 feet, depending on the jurisdiction. The exhaust from a natural-gas or propane generator is not toxic like car exhaust, but it's warm and can be annoying blowing into a window. The setback rule is partly about comfort and partly about ensuring the generator intake (if it's powered by atmospheric air) doesn't pull in exhaust air. Propane tanks have larger setbacks — usually 10 feet from windows and doors and 5 feet from the building foundation. Check your local building code for exact setback distances, and verify with your building department when you file the permit. If your property is small and setbacks are tight, ask whether a variance is available, but expect the answer to be no — setbacks exist for safety and comfort.
Do I need a permit for a portable generator that I store at home but only use during emergencies?
No. A portable generator — one you can pick up and move, with a gasoline or propane tank you refuel — does not require a permit, even if you store it at home. Once you permanently install a generator (mount it on a pad, wire it to an automatic transfer switch, and integrate it with your electrical system), it crosses the threshold from portable to standby, and a permit is required. The distinction is the permanence and integration with the home's electrical and fuel systems. If you're using a portable generator and manually plugging it in with a heavy-duty extension cord, you don't need a permit. But if you're hardwiring it, installing an ATS, or connecting it to a propane tank, you do.
Ready to move forward with your standby generator?
Start by calling your local building department's permit desk and describing your project: fuel type (natural gas, propane, diesel), intended capacity (in kW), automatic transfer switch (yes or no), and the location on your property where you plan to install it. A 5-minute conversation will tell you exactly which permits you need, what documents to file, the fee, and the typical timeline. Ask if they offer an online portal for filing or if you need to submit in person. Write down the contact name and get a case number if possible. Once you have the permit requirements, hire a licensed electrician and get a quote for the installation — they'll coordinate the electrical design and pull the electrical permit. Many jurisdictions process residential generator permits quickly and predictably, so the wait time is usually just plan-review time, not back-and-forth corrections.
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