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How Much Does It Cost to Install a Whole House Generator?

To answer the question posed above it would be easy to simply dismiss it and say, “it depends”. Whilst this is true, and it very much does depend on a number of different factors, you will need far more detail to truly find out about any costs involved in the installation of a generator for your whole house.

We want to give you as detailed an answer as possible, and we will be using this article to do this. We cannot promise you will finish this article with one solid figure in mind, because as we have stressed, the end cost will vary depending on many different things.

The average cost to install a whole-house generator in 2021 is between $9000 and $15’000 depending on the size of your home. The location also plays a part in the cost. Makes and models can also vary with about 15-20% difference in overall cost.

However, what this article will do is give you an idea of exactly where you might incur costs and equip you to work out a rough estimate. 

What Comes into the Price? 

Will you need a standby or portable generator? 

The first thing you need to consider that can have a huge effect on the overall price is what type of generator you need. The two main types are portable and standby generators.

Portable generators are much cheaper, however (and this is a big ‘however’!), they are often not as reliable as standby generators. There is, of course, no right or wrong.

To go into further detail, a portable generator needs to be switched on by you and refueled. It will not come on automatically, meaning that if you are not there when the power goes out, there is nothing you can do.

That being said, there are portable generators that can be activated via a smartphone app, and these are becoming increasingly popular. You cannot fuel it via the app, of course, but it can be safely switched on if you happen to be away from home for the time being. 

A standby generator is one that comes on as soon as the power goes out. It is triggered by power outages and kicks in automatically. They can often deal with more power than their portable counterparts.

However, the downside is that they are often far more expensive, especially if you have a house that is larger than your typical condo size. 

We found these on Amazon

Make & Model
Editors Pick
Generac 70422
Natural Gas
Champion 100294
Low Price
Kohler 20RESCL-100LC16
Budget Option
Briggs & Stratton 40531
Ready to go option
Generac 70361
Image
Generac 70432 Home Standby Generator Guardian...
Champion Power Equipment 100294 Home Standby...
Kohler 20RESCL-100LC16 Air-Cooled Standby...
Briggs & Stratton 40531 12kW Standby Generator...
Generac 70361 Home Standby Generator 16/16 kw...
Kw
22/19.5kW
14-kilowatt
18 - Kilowats
12 - Kilowats
16 - Kilowats
Power Source
LP or natural gas
Natural gas
Propane-powered
Dual Fuel
Gas Powered
Size
48 x 25 x 29 inches
50.00 x 30.10 x 40.20 inches
48.00 x 26.20 x 29.00 inches
39.00 x 33.50 x 44.80 inches
48.00 x 25.00 x 29.00 inches
Weight
476 pounds
493.90 lbs
560.00 lbs
404.00 lbs
458.00 lbs
Noise Level
62 dba noise level
63 dba noise level
64 dba noise level
62 dba noise level
63 dba noise level
Extra Features
Mobile Phone Monitoring
-
100% corrosion-proof enclosure
-
Mobile Monitoring
Warranty
5 Year Warranty
10-year limited and FREE lifetime technical support.
5 Year Warranty
5 Year warranty
5 Year warranty
Transfer switch included?
Transfer Switch Not Included
Yes
100 Amp Transfer Switch
200 amp automatic transfer switch
100 amp switch
Editors Pick
Make & Model
Generac 70422
Image
Generac 70432 Home Standby Generator Guardian...
Kw
22/19.5kW
Power Source
LP or natural gas
Size
48 x 25 x 29 inches
Weight
476 pounds
Noise Level
62 dba noise level
Extra Features
Mobile Phone Monitoring
Warranty
5 Year Warranty
Transfer switch included?
Transfer Switch Not Included
Latest Price
Natural Gas
Make & Model
Champion 100294
Image
Champion Power Equipment 100294 Home Standby...
Kw
14-kilowatt
Power Source
Natural gas
Size
50.00 x 30.10 x 40.20 inches
Weight
493.90 lbs
Noise Level
63 dba noise level
Extra Features
-
Warranty
10-year limited and FREE lifetime technical support.
Transfer switch included?
Yes
Latest Price
Low Price
Make & Model
Kohler 20RESCL-100LC16
Image
Kohler 20RESCL-100LC16 Air-Cooled Standby...
Kw
18 - Kilowats
Power Source
Propane-powered
Size
48.00 x 26.20 x 29.00 inches
Weight
560.00 lbs
Noise Level
64 dba noise level
Extra Features
100% corrosion-proof enclosure
Warranty
5 Year Warranty
Transfer switch included?
100 Amp Transfer Switch
Latest Price
Budget Option
Make & Model
Briggs & Stratton 40531
Image
Briggs & Stratton 40531 12kW Standby Generator...
Kw
12 - Kilowats
Power Source
Dual Fuel
Size
39.00 x 33.50 x 44.80 inches
Weight
404.00 lbs
Noise Level
62 dba noise level
Extra Features
-
Warranty
5 Year warranty
Transfer switch included?
200 amp automatic transfer switch
Latest Price
Ready to go option
Make & Model
Generac 70361
Image
Generac 70361 Home Standby Generator 16/16 kw...
Kw
16 - Kilowats
Power Source
Gas Powered
Size
48.00 x 25.00 x 29.00 inches
Weight
458.00 lbs
Noise Level
63 dba noise level
Extra Features
Mobile Monitoring
Warranty
5 Year warranty
Transfer switch included?
100 amp switch
Latest Price

Last update on 2021-04-28 / Affiliate links / Images from Amazon Product Advertising API

Fuel Type 

The type of fuel you use to power your generator also has a direct impact on the overall cost. Using any fuel will add on regular money to the cost, and of course, some are more expensive than others.

Typically, diesel generators cost a lot more upfront too. They can cost as much as $15000 to purchase outright, and then with the added costs whenever you need to buy more fuel. A cheaper option is gasoline.

Gasoline generators are around the $3000 mark, five times cheaper than diesel. However, when considering the fact that diesel is far more efficient than gasoline, you may find that in the long run, the costs even themselves out. 

There are also other options such as solar powered and natural-gas-powered generators. Solar powered generators are often very expensive, but since they do not rely on any fuel to keep them going, they can be a better choice in the long run.

This is especially helpful if you see yourself relying on your generator a lot, for example, if you are moving somewhere without access to a grid and you need your generator daily.

Natural gas can also be a good option as it is slightly more environmentally friendly than diesel and gasoline, falling between the prices of the two. 

whole house generator

Capacity – How much power will you need? 

All homes will need a different capacity. To get an accurate estimate of how much capacity or power you will need from your generator, you should seek the advice of a professional.

This is because getting it wrong could be dangerous – lethal even! If you underestimate because it is cheaper to get a less powerful generator then you could overload it. If you overload your generator it can easily cause a fire. 

It may feel tempting then to overestimate how much you will need, but this will just wind up with you having to pay too much for something you do not need.

This is because the more power a generator has, the more expensive they are. Getting a professional to help you work it out will likely work out cheaper in the long run. 

Use our wattage calculator to figure out how much power you really need.

Labor Costs for the Installation 

This is a biggie! We’re just going to put it to you straight – no matter how good your electrician cousin is, and no matter how handy you are at DIY, if you have no prior experience of installing a whole house generator, you should not be putting one in your home yourself!

Even the most qualified electrician should not be used if they have never fitted a generator before. When you are looking for a professional to install your whole house generator, you should take care to quiz them on how many generators they have successfully fitted. 

The truth is a good installation person is going to be well worth the money. It is thought that the installation of a generator system can cost around 75% of the generator itself. So, say you have a generator that is $10000, you can expect to pay around $7500.

This is, of course, a rough estimate, and these prices will vary state to state and electrician to electrician. However, we cannot stress enough the importance of ensuring it is fitted by someone who is qualified. It is worth the money to ensure this! This is not the place to cut costs. 


Final Verdict 

As you can see, it can be hard to pinpoint an exact price for the installation of a whole house generator.

What remains true is that these prices will vary depending on many factors such as the generator itself, how powerful it is, what fuel it will be using, whether it is portable or standby, and of course, the labor costs. Based on our research, the final figures are very broad, being anything from $9000 to around $15000 maxing out at $25k for larger homes.

What we hope to have done is given you a breakdown of all of the things that will be taken into consideration for the final cost and given you some pointers about how to cut costs (e.g., by choosing a portable generator if that suits you, or a more efficient fuel type).


All the article on Oofgrid offer help and practical advice for using and purchasing a portable generator. However, We are enthusiasts and not qualified electricians. Always seek professional advice when working with electrical or Petrol appliances.