For many years, upgrading a residential electrical service from 100 amps to 200 amps was considered a substantial step.
For many homes, it still is.
But residential electrical demand is changing.
Electrilex is seeing more West Island homeowners asking about 320A and 400A electrical services as homes add larger and more numerous electrical loads. An EV charger may be only the beginning. A home can also have a second EV, heat pumps, electric heating, a pool, hot tub, renovated kitchen, finished basement, home addition and other substantial electrical equipment.
At some point, the question changes from:
“Should we upgrade from 100A to 200A?”
to:
“Will 200A actually provide enough capacity for the home we are creating?”
For some properties, the appropriate solution may be 320A or 400A.
But larger is not automatically better. Choosing the appropriate electrical service capacity starts with understanding the actual requirements of the home.
Why Are Some Homes Moving Beyond 200A?
Residential electrical demand has changed significantly. Homes increasingly rely on electricity for equipment and functions that may previously have used other energy sources—or simply did not exist. At the same time, homeowners are renovating and expanding properties while expecting the electrical system to accommodate both today's equipment and tomorrow's additions.
One individual load may not create the need for a larger electrical service.
It is the combination of loads that matters.
A larger West Island home could potentially include:
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One or more Level 2 EV chargers
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Heat pumps
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Electric heating
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Electric water heating
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Pool equipment
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A hot tub or spa
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A renovated kitchen with substantial electrical equipment
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A finished basement
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A home addition
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Garage or workshop loads
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Other high-demand residential equipment
As these loads accumulate, even a 200A service can require closer evaluation.
Is a 200A Service Still Enough for Many Homes?
Yes.
A 200A electrical service provides substantial capacity and remains an appropriate solution for many residential properties. The important point is that 200A should not automatically be assumed to be sufficient simply because it is larger than 100A.
Every home is different.
A moderately sized home with an EV charger and heat pump can have very different electrical requirements from a large property with extensive electric heating, two EVs, a pool, hot tub and additional electrical equipment. The decision should therefore come from the home's electrical requirements rather than choosing a service size first and trying to make everything fit afterward.
What Is a 320A Residential Electrical Service?
A 320A service provides significantly greater available capacity than a conventional 200A residential service and can be considered for homes where the calculated electrical demand and future requirements justify moving beyond 200A. It can be particularly relevant when a property is undergoing significant electrification or when several large electrical loads need to be accommodated.
That does not mean every large house requires 320A. It means there is another residential service-capacity option when 200A does not provide the appropriate solution.
For homeowners planning substantial upgrades, evaluating this before renovation or equipment installation begins can prevent electrical capacity from becoming an afterthought.
When Might a Home Need 400A?
Some residential properties have electrical requirements that justify considering approximately 400A of service capacity. These tend to be larger or particularly high-demand homes where multiple substantial electrical systems operate within the same property.
For example, consider a home planning:
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Two EV chargers
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Extensive electric heating or heat-pump equipment
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Pool and hot-tub equipment
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A substantial kitchen renovation
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A finished basement or home addition
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Additional future electrification
No single item on that list automatically means the home requires 400A. Together, however, significant electrical loads can change the service-capacity discussion.
This is where proper planning becomes particularly important.
Two EVs Can Change the Conversation
One Level 2 EV charger already represents an important load to consider. For families moving toward two electric vehicles, the planning becomes more involved.
The answer is not automatically to double everything.
Charging behaviour, charger output, available electrical capacity and energy-management options can all affect the appropriate design. But if a home is already heavily electrified, adding multiple EV chargers can contribute to the case for greater service capacity. This is one reason Electrilex prefers to understand the homeowner's longer-term plans instead of looking only at the vehicle being purchased today.
The electrical system should make sense for the home as a whole.
Heat Pumps and Electric Heating Matter Too
EVs receive a great deal of attention when homeowners think about electrical capacity, but heating can be equally important. West Island homes can have substantial heating requirements. Heat pumps, electric backup heating, baseboard heating and other electrically powered systems all contribute to the overall electrical demand.
When heating is combined with EV charging and other large residential loads, service capacity deserves careful consideration. A homeowner may therefore begin the conversation because of an EV charger while discovering that the more important question is the overall electrical plan for the property.
Pools, Hot Tubs and Outdoor Electrical Loads
Pools and hot tubs add another layer to residential electrical planning. Pumps, heaters and associated equipment can contribute meaningful electrical loads, particularly when combined with the rest of an increasingly electrified home.
A property that already has significant electric heating and EV charging may need to consider these additions differently from a home with relatively modest existing demand. Again, the important factor is the complete electrical picture.
Major Renovations Are the Right Time to Think Ahead
A major renovation is one of the best times to consider long-term electrical capacity.
- Walls may be open.
- New circuits are being planned.
- Heating or cooling may be changing.
- The kitchen may be redesigned.
- A basement may be finished.
- An addition may be constructed.
- EV charging may be part of the project even if the vehicle has not yet been purchased.
Instead of treating each new electrical load as a separate project, a major renovation creates an opportunity to look at the home as a complete electrical system.
If the existing service is already approaching its practical capacity, upgrading only enough to satisfy today's project can create another capacity problem later.
Why Load Calculation Comes Before Service Size
A homeowner cannot determine the appropriate electrical service size simply by counting appliances, adding breaker ratings or looking at empty spaces in the electrical panel. The electrical demand of a home needs to be evaluated properly. A load calculation considers the electrical requirements of the property and helps determine the capacity needed for the existing and proposed installation. This becomes particularly important when considering 320A or 400A service.
The goal is not:
“Let's install the biggest electrical service possible.”
The goal is:
“Let's determine the appropriate capacity for this home and the way it will actually be used.”
That distinction matters.
200A vs. 320A vs. 400A
There is no universal rule saying a particular size of house automatically needs a particular service size. A home's electrical requirements depend on the equipment installed and how the property is configured and used.
In general:
200A can provide substantial capacity for many modern homes and is a common step up from an older 100A service.
320A can become relevant when a home's calculated demand and planned electrification move beyond what a 200A service can appropriately accommodate.
400A may be considered for particularly high-demand residential properties where multiple major electrical loads require still greater overall capacity.
These are not upgrades that should be selected from a menu based simply on which number sounds more future-proof. They require proper evaluation and planning.
Why Future Planning Matters More at These Service Sizes
Moving to a larger residential electrical service is a significant infrastructure decision. That makes it worthwhile to discuss what may happen to the property over the next several years.
- Will there be a second EV?
- Could heating become fully electric?
- Is a pool or hot tub planned?
- Will the kitchen be substantially renovated?
- Could the home be expanded?
- Are there additional large electrical loads likely to be installed?
Not every future possibility needs to be accommodated indefinitely. But known or realistic plans should be part of the conversation before choosing the service capacity.
Utility Coordination Is Part of the Project
A major residential service upgrade involves more than the electrical panel inside the home. The existing service arrangement, service entrance equipment, metering, conductors, grounding and bonding, and utility requirements all need to be considered. Higher-capacity residential services can also require more planning than a straightforward panel replacement.
Electrilex handles the electrical portion of the service upgrade and the required coordination with Hydro-Québec for our residential service projects. The exact scope depends on the individual property and the service being installed.
Does a Larger Service Automatically Lower Your Electricity Costs?
No.
The amperage rating represents available electrical capacity. It does not mean the home continuously consumes that amount of electricity. A larger electrical service does not, by itself, make a home use less electricity. Energy consumption depends on the equipment in the home and how it is operated. Service capacity and energy consumption are related concepts, but they are not the same thing.
Should You Install 400A Just to Be Safe?
Not necessarily.
Future planning is important, but oversizing without a reason is not the objective. A homeowner should understand the likely electrical requirements of the property, determine the calculated load and consider realistic future additions.
Sometimes 200A is appropriate.
Sometimes the electrical plan points toward 320A.
And some high-demand homes may justify 400A.
The recommendation should follow the home—not the other way around.
Start With the Home You Are Building Toward
West Island homes are changing. EVs, heat pumps, renovations, additions and greater electrification are changing what homeowners expect from residential electrical systems. That makes electrical service planning increasingly important.
If you are already investing in a substantial service upgrade, it makes sense to consider more than the immediate project. At Electrilex, we look at the existing installation, current electrical demand and the homeowner's realistic future plans before recommending a service capacity.
For many homes, 200A will remain an appropriate solution. For others, 320A or 400A may provide the capacity required for the next stage of the property.
The right answer begins with an assessment—not an assumption.
Frequently Asked Questions
Is 200 amps enough for a modern house?
For many homes, yes. However, the answer depends on the calculated electrical demand, existing equipment and planned additions. Some high-demand homes may require capacity beyond 200A.
Why would a house need 320A service?
A 320A service may be considered when the combined electrical demand of the property exceeds what a 200A service can appropriately accommodate. Multiple EV chargers, electric heating, heat pumps, pools, hot tubs and substantial renovations can all contribute to the overall demand.
Can a residential home have 400A electrical service?
Yes. Some high-demand residential properties may require approximately 400A of electrical service capacity. The need should be established through proper evaluation and planning.
Do two EV chargers mean I need 400A?
Not automatically. EV charging is only one part of the home's overall electrical demand. Charger configuration, energy management and the other loads in the property all need to be considered.
Should I choose 400A now for future-proofing?
Not simply because it is larger. Future plans should be considered, but the service capacity should be appropriate for the home's actual and reasonably anticipated electrical requirements.
Can Electrilex upgrade residential services beyond 200A?
Electrilex works with residential electrical service upgrades including 200A, 320A and 400A applications, depending on the requirements and conditions of the property.
Planning a 200A, 320A or 400A Electrical Service in the West Island?
If you are planning major electrification, multiple EV chargers, extensive electric heating, a substantial renovation or other high-demand additions, electrical service capacity should be considered early in the project.
Electrilex specializes in residential electrical work throughout Montreal's West Island.
With more than 20 years of residential experience, we assess the existing installation, consider the electrical loads and discuss what you are planning before recommending the appropriate direction.
The objective isn't to install the largest service. It's to install the right service for the home.