Backup Generators · Service

Whole home generator installation, start to inspection

A permanently installed standby generator is a construction project with an electrician and a gas fitter in it, not an appliance delivery. Here is the sequence, the two things that most often derail it, and the honest cases where the outages you get do not justify the spend.

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In short

What is whole home generator installation?

A whole home generator is a permanently installed machine that sits outside on a pad, runs on natural gas or propane, and starts automatically within seconds of an outage through a transfer switch. Installing one is a two-trade project: an electrician for the switch and the connection to your service, and a gas fitter or propane supplier for the fuel. The two things that most often stall it are where it is allowed to sit and whether your existing gas supply can feed it.

Triggers

Signs you need whole home generator installation

Your area loses power for days rather than hours — ice storms, hurricanes, wildfire de-energisation, or a rural feeder with a long repair queue
You are on a well, so an outage means no water, no toilets and no washing, and the pump is a hard-wired load a cord cannot reach
You have a basement with a sump pump and a high water table, where a long outage during heavy rain is a flooded basement
Someone in the house relies on powered medical equipment, or on refrigerated medication
You already own a portable generator and have discovered that dragging it out in a storm at night is a thing you will not reliably do

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The job

How whole home generator installation actually works

Site survey before any model is quoted

A proper first visit looks at four things at once: where the machine can legally and practically sit, where the electrical service and panel are, where the gas meter or a propane tank would go, and how far apart all of those are. Distance costs money in both trades, and the cheapest position electrically is often the worst one for exhaust.

Watch for: A quote produced from a phone call and a square-footage figure. Everything expensive on this job is site-specific, and a number given without a visit is a number that will change.
Sizing — and deciding whether "whole home" means the whole home

Sizing works from what you want running at once plus the starting surge of every motor load, not from house size. There is a real fork here: buy a machine big enough for the theoretical peak, or buy a smaller one and add load management so the air conditioning, water heater, range and dryer never start together. The second is frequently cheaper for the same lived experience.

Watch for: Sizing by square footage. It is the fastest sales method and it ignores whether you have electric or gas heat, one air conditioner or two, a well pump, or an electric range — the things that actually set the number.
Confirm the fuel supply can actually feed it

This is the most common project-stopper and it deserves to be checked early. A generator is one of the largest gas loads a house can have, and an existing meter and service line sized for a furnace, a water heater and a range may not have the capacity left. The fix — a larger meter or an upgraded service from the utility — is a separate application with its own timeline.

Watch for: A gas load calculation that is not done, or done after the deposit. Ask for it in writing before you commit, along with who applies to the utility if a meter upgrade is needed and how long that typically takes locally.
Establish the setbacks, and the exhaust direction

Manufacturers specify minimum clearances from the building and from combustible material, and codes set separation distances from windows, doors and air intakes. The reason is carbon monoxide: exhaust from a machine that runs for days must not find a way into the house. On top of that, many jurisdictions and most homeowner associations have their own rules about placement.

Watch for: A location chosen to shorten the cable run, sitting under a bedroom window or beside a fresh air intake. This is the safety decision on the whole project and cable length is not a good enough reason to compromise it.
Check the noise rules and be honest about the neighbours

These machines are not quiet, and they exercise themselves on a schedule as well as running during outages. Many municipalities have noise ordinances that apply, and associations often add their own limits. Modern enclosures are much better than older ones, and manufacturers publish sound levels at a stated distance — ask to hear one running rather than reading a figure.

Watch for: Placement against a shared boundary or under the neighbour's bedroom. It is the complaint that arrives after the machine is bolted to a slab and the least fixable one.
Pad, permits and scheduling the two trades

The machine sits on a level pad — a poured slab or a manufactured composite base — raised clear of standing water and, in cold regions, above expected snow depth. Then the paperwork: electrical and gas permits, sometimes a zoning or association approval, and inspections that have to be scheduled around both trades and the utility.

Watch for: A pad set at grade in a spot that puddles, or an installation that quietly skips permits. Unpermitted gas and electrical work surfaces at sale and can complicate a claim after a fire.
Installation, fuel connection and electrical tie-in

The machine is set, the gas line run and pressure-tested, the transfer switch installed at the panel or the service, and the control wiring run between switch and machine. Gas pipe sizing over the distance matters as much as the meter capacity — a long undersized run starves the engine under load even when the meter is adequate.

Watch for: Pipe sized for the length on paper but routed a much longer way in practice. Ask for the run length used in the sizing to match the run that got installed.
Commissioning, a live outage test, and the handover

The installer starts the machine, checks it under load, sets the exercise schedule, and — the part that matters — kills the utility supply at the main and lets the whole system perform a real outage from start to transfer to return. You should watch it, be shown how to shut it down manually, and be told what the normal noises are.

Watch for: Handover with no live test and no manual-shutdown demonstration. You need to know how to stop the machine before you need to know how to stop the machine.

Money

What does whole home generator installation cost?

A whole home generator installation is a five-figure project in most cases once the machine, the transfer switch, the pad, the gas work and the permits are counted, and the site conditions move it more than the model does. A gas meter upgrade adds separately. See the generator cost guide.

See the full whole home generator installation cost guide — by material, size and region →

Straight answer

When whole home generator installation is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

Your outages are short and infrequent. Look up your actual history rather than your impression of it — a few hours once or twice a year is an argument for a battery, a small portable or better torches, not for a five-figure gas-fired machine that exercises itself every week for a decade.
You have no natural gas supply and no room for a propane tank. Setbacks apply to tanks as well, and a small tank means refills mid-outage, which is exactly when deliveries are hardest to get. On a tight urban lot this frequently ends the conversation.
You already have solar and are considering storage. A home battery covers the same critical loads silently, with no fuel, no exhaust, no exercise cycle and no annual service, and it does something for you on the other 360 days of the year. It runs out where a generator does not, so compare them on your actual outage lengths rather than accepting either sales pitch.
Your association or your setbacks will not allow a workable position. Establish this before you sign anything. Getting through the survey, the deposit and the equipment order to discover the only compliant location is 90 feet from the panel is an expensive way to learn it.
Nobody will be maintaining it. A standby generator is an engine that sits outside for years and is asked to work perfectly on one specific night. Without an annual service and a battery that gets replaced on schedule, the most common outcome is a machine that does nothing when the lights go out.
You are moving within a couple of years. It does add saleable appeal in areas with a genuine outage problem, and it rarely returns its installed cost anywhere else. If the reason is resale rather than your own comfort, the numbers are usually against you.

Your options

Types of whole home generator installation

Fuel: natural gas or propane

The decision that follows from what your site already has. Set out in full on the fuel page.

The transfer switch

Automatic versus manual, whole-service versus essential circuits, and load management.

Standby versus portable

The upstream decision, compared honestly on the comparisons archive.

Brands and dealer networks

Who services it locally matters more than the badge.

Compare backup generators options side by side →

Before you sign

What to check when hiring for whole home generator installation

Will you do a gas load calculation before I commit, and show it to me?

The single most common project-stopper. If your meter cannot feed the machine, you need to know before the deposit — and you need to know who applies for the upgrade and how long it takes locally.
How did you size this, and would load management let me buy a smaller machine?

Sizing should come from a load list with starting surges, never from square footage. Asking about load management directly can materially change the price.
Where exactly will it sit, and what setbacks and clearances apply?

Distance from windows, doors and air intakes is the carbon monoxide question and it is the safety decision on this project. Get the position and the reasoning marked on the quote.
How loud is it at my property line, and can I hear one running?

Published sound figures are measured at a stated distance under stated conditions. Standing next to a running machine tells you more.
Which permits are needed, who pulls them, and are the inspections in your price?

Two trades can mean two permits and two inspections. Unpermitted gas and electrical work is a problem at sale and after a fire claim.
What is the lead time on this model, and what is the schedule across both trades and the utility?

Equipment lead times and utility timelines run this project, not the labour. You want a realistic date rather than an optimistic one, particularly if you are buying ahead of a storm season.
What does the first year of maintenance cost, and who does it?

It is an engine with a service schedule. Find out what an annual visit costs and whether the installing dealer services what they sell, because that relationship is what determines whether the machine works in five years.
Will you kill the main and run a live outage test with me present?

The only real proof the whole system works together. It is also when you learn how to shut it down by hand, which is a thing you want to know in advance.

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Local pros

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Related work

Often done at the same time

Generator Transfer Switch Installation

The switching half of the project

Natural Gas Generator Installation

The fuel decision and the gas work

Generator Maintenance

What keeps it working in year five

Portable Generator Setup

The cheaper arrangement, honestly assessed

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FAQ

Whole Home Generator Installation — questions people ask

Still have a question? Talk to our team →

What size whole home generator do I need?

It comes from a load list, not from your square footage. Someone should be adding up what you want running simultaneously and then checking the starting surge of every motor load in it, because a well pump or an air conditioning compressor draws several times its running current momentarily. Then there is a genuine choice: size the machine for that peak, or size it smaller and add load management so the big loads never start together. The second option is often cheaper for the same experience.

How long does the whole installation take?

The physical work is usually a small number of days across two trades, but the project is rarely limited by labour. Equipment lead times, permit issue, inspection scheduling and — where a larger gas meter is needed — the utility's own timeline are what set the calendar, and any one of them can add weeks. If you are buying ahead of a specific storm season, start considerably earlier than the labour estimate suggests.

Where can a standby generator legally be placed?

It has to satisfy the manufacturer's clearances from the building and from anything combustible, and code separation distances from windows, doors and air intakes, because the exhaust contains carbon monoxide and the machine may run for days. On top of that, many municipalities have their own placement and noise rules and most homeowner associations add theirs. Establish the workable positions before you order equipment — this is the constraint that most often reshapes a project.

Will my gas meter handle a generator?

Not always, and it is the most common thing that stalls these installations. A generator is one of the biggest gas loads a house can have, and a meter and service sized for a furnace, water heater and range may have no capacity left. A gas load calculation answers it, and where the answer is no, a meter or service upgrade is a separate application to the utility with its own timeline. Get the calculation done before you pay a deposit.

How noisy is a standby generator?

Noticeably noisy — it is an engine in an enclosure a few feet from a wall — though modern units are much better than older ones and manufacturers publish sound levels measured at a stated distance. Remember that it also runs a scheduled self-test every week or so, which is what your neighbours will actually hear most of the time. Many jurisdictions and associations have noise limits that apply. Ask a dealer to let you stand next to one running before you decide on a position.

How often does a whole home generator need servicing?

It follows the manufacturer's stated schedule, and that schedule is based on both elapsed time and running hours — so a machine that has sat idle all year still has service due. Oil, filters, spark plugs and the battery are the recurring items, and the battery is far and away the most common reason a standby generator fails to start when it is needed. Treat the annual service as part of the running cost of owning one, not as optional.

Does a whole home generator run on its own if nobody is home?

Yes, and that is much of the point of it. With an automatic transfer switch, the system detects the outage, starts the engine, waits for it to stabilise, transfers the load, and reverses all of that once utility power has returned and held steady. It is what makes standby power meaningful for an unoccupied property, a house that would freeze, or a basement whose sump pump has to keep running through a storm.