Choosing between 100 amp and 200 amp electrical service affects your property’s safety, capacity, and long-term value. This guide explains the key differences, when Toronto homeowners and commercial property owners should consider upgrading, and what Ontario Electrical Safety Code requires. If your property runs EV chargers, electric heating, or modern appliances, 200 amp service is typically the right move.
What Does Electrical Service Size Mean?
Electrical service size, measured in amperes (amps), determines how much current your property can safely draw from the utility grid at one time. It is not just about your breaker panel. The full electrical service includes the utility connection, service conductors, meter base, grounding system, main disconnect, and distribution panel.
When you exceed the capacity of your service, the system cannot safely handle the load. That creates overheating risk, frequent tripping, and in older setups, a real fire hazard. Understanding service size is the first step in making a smart, code-compliant decision for your Toronto property.
The Electrical Safety Authority (ESA) governs all electrical work in Ontario and sets the standards every licensed contractor must follow.
100 Amp Electrical Service: What It Covers
For decades, 100 amp service was the standard for Toronto homes. Many properties built before the 1990s still run on it, and for some lower-demand buildings it remains adequate.
Properties Where 100 Amp May Still Be Sufficient
- Older homes with gas heating and gas cooking appliances
- Smaller properties with minimal air conditioning needs
- Buildings with no EV chargers or high-draw electrical equipment
- Cottages or secondary structures with limited electrical use
Limitations of 100 Amp Service
The reality for most Toronto properties today is that 100 amp service struggles to keep up. Modern electrical loads, including heat pumps, in-unit laundry, and home office equipment, push older services close to their limit.
- Limited circuit capacity for renovations or additions
- Inability to support EV chargers without load management or upgrade
- Breakers tripping under normal daily loads
- No headroom for future electrical improvements
If you are planning a basement finish, kitchen remodel, or any significant addition, a 100 amp service will almost certainly require upgrading to meet the Ontario Electrical Safety Code.
200 Amp Electrical Service: The Modern Standard
200 amp service has become the baseline for new residential construction across the Greater Toronto Area and is standard for many commercial installations. It provides double the capacity of a 100 amp service, which translates directly to more circuits, greater load flexibility, and improved long-term reliability.
Key Benefits of 200 Amp Service
- Supports EV charger installation without overloading the system
- Handles electric heating, heat pumps, and central air conditioning simultaneously
- Provides enough capacity for kitchen remodels, home additions, and workshops
- Reduces overheating risk by operating well below maximum capacity
- Improves long-term property value and passes electrical inspections with fewer issues
Phaze-In Electric handles full panel upgrades from initial load assessment through to ESA inspection, so every step of the process meets Ontario code.
Key Differences: 100 Amp vs 200 Amp Side by Side
Capacity and Load
The core difference is simple: 200 amp service allows twice the electrical load. That means more circuits running simultaneously without overloading the system. For a Toronto homeowner running a heat pump, EV charger, and modern kitchen, the math clearly favors 200 amp service.
Safety and System Health
Running consistently near capacity stresses every component in your electrical system. Wires and breakers operating under sustained high load degrade faster and create overheating risk. A 200 amp service gives your system meaningful headroom, which directly reduces wear and improves safety over time.
The Canadian Standards Association (CSA) sets the electrical standards that underpin Ontario code requirements, including service sizing minimums for residential and commercial applications.
Long-Term Flexibility
A 100 amp service can become a hard ceiling on your property. Any significant renovation, EV adoption, or equipment addition may require a full service upgrade anyway, which means double the disruption and cost. Upgrading to 200 amp service now avoids that bottleneck.
Property and Resale Value
In Toronto’s real estate market, 200 amp service is increasingly expected. Home inspectors flag undersized services, and some buyers and lenders treat it as a condition of purchase. A 100 amp service can affect negotiating position and resale timelines.
When Should You Upgrade Your Electrical Service?
EV Charger Installation
One of the most common reasons Toronto property owners upgrade their service is to support a new EV charger. A Level 2 unit typically draws 32 to 48 amps continuously, and most 100 amp services cannot safely absorb that load alongside regular household use.
Renovations and Additions
Kitchen upgrades, basement finishing, home additions, and commercial space expansions all add meaningful electrical load. The Ontario Electrical Safety Code requires that new circuits and panels meet current standards, which often triggers a service upgrade assessment.
Signs Your Service Is Undersized
- Breakers trip under normal daily loads
- Lights dim when large motors or appliances start
- Warm, buzzing, or discoloured panel components
- No available space for new breakers
- Insurance providers or inspectors flagging the existing setup
If you notice any of these issues, a licensed assessment from Phaze-In Electric will confirm whether a service upgrade is the right next step before you add any new circuits.
Ontario Electrical Safety Code and Permit Requirements
All electrical service upgrades in Ontario must be permitted through the ESA and inspected before the work is considered complete. This is not optional, and unlicensed work creates liability for property owners, insurance issues, and safety risks.
A compliant service upgrade covers utility coordination for disconnect and reconnect, correct grounding and bonding to current code, proper service conductor sizing, and inspection sign-off from the ESA.
The Ontario Building Code and the Ontario Electrical Safety Code work together to define the scope of work that triggers permits and inspections on residential and commercial properties.
For commercial property owners and managers, commercial work at Phaze-In includes full permitting and utility coordination so nothing falls through the cracks on larger or more complex installations.
Residential vs Commercial Electrical Service Considerations
Residential Properties
For most Toronto homeowners, 200 amp service is the right choice whether you need it immediately or not. The incremental cost of upgrading now versus later is almost always lower, and the benefits, from EV readiness to improved resale position, are immediate.
Commercial Properties
Commercial electrical service requirements vary significantly based on equipment, occupancy, and use. Many commercial operations need 400 amp service or higher. A precise load calculation from a licensed Master Electrician determines the right service size. Guessing at this level creates code violations, operational failures, and insurance complications.
Restaurants, clinics, and property management clients can review the full scope of commercial services Phaze-In offers across the GTA, including service sizing assessments tailored to each building’s actual load profile.
Why a Licensed Electrician Assessment Matters
Choosing a service size is not a decision to make based on a quick online search or a neighbour’s suggestion. A licensed electrician calculates your actual electrical load based on current usage, planned equipment, and future needs, then recommends the right service size with a written scope of work.
Phaze-In Electric Ltd. is a fully licensed, ESA-certified electrical contractor in North York, Toronto, and the Greater Toronto Area. Led by Master Electrician Andrew Spano, who has held his Master Electrician license since 2015, the team brings residential and commercial expertise to every project.
Every service upgrade is handled with the same standard of care that applies across all residential work at Phaze-In: code-compliant installation, proper permitting, and transparent communication from the initial site visit through to final inspection.
Making the Right Electrical Service Decision for Your Toronto Property
100 amp service still works for a narrow range of properties with low electrical demand. For the majority of Toronto homes and commercial spaces today, 200 amp service delivers the capacity, safety margin, and future flexibility that modern electrical use requires.
Whether you are planning an EV charger installation, completing a renovation, or simply assessing the state of an older electrical system, a professional load calculation from a licensed electrician gives you a clear answer and a safe path forward.
Phaze-In Electric Ltd. serves North York, Toronto, Etobicoke, Vaughan, Markham, Richmond Hill, Mississauga, and Oakville. Browse Phaze-In Electric Ltd for answers to common questions about electrical upgrades, or contact the team directly to schedule a licensed site inspection.
Frequently Asked Questions
1. What is the difference between 100 amp and 200 amp electrical service?
100 amp service allows a maximum of 100 amperes of current to flow into your property at one time, while 200 amp service doubles that capacity. In practical terms, 200 amp service supports more circuits simultaneously, handles higher electrical loads, and provides greater safety headroom. For most Toronto homes with modern appliances, an EV charger, or electric heating, 200 amp service is the appropriate choice.
2. Do I need to upgrade my electrical service to install an EV charger in Toronto?
It depends on your current service size and existing electrical load. Many 100 amp services cannot safely support a Level 2 EV charger without a service upgrade or load management system. A licensed electrician will calculate your available capacity and confirm whether an upgrade is required before installation. Phaze-In Electric handles both the service assessment and the charger installation.
3. Does an electrical service upgrade require a permit in Ontario?
Yes. All electrical service upgrades in Ontario require an ESA permit and must pass an ESA inspection before the work is deemed complete. Utility coordination is also required for the disconnect and reconnect. Hiring a licensed electrical contractor who pulls the permit protects you legally, satisfies your insurer, and confirms the work meets the Ontario Electrical Safety Code.
4. How long does a 100 amp to 200 amp electrical service upgrade take?
A typical residential service upgrade in Toronto takes one day for the electrical work itself. Utility coordination for the power disconnect and reconnect adds scheduling time, usually a few days to a couple of weeks depending on your utility provider’s availability. Planning the upgrade ahead of any renovation or EV charger installation avoids delays.
5. Will upgrading to 200 amp service increase my property value in Toronto?
A 200 amp service is now considered standard by most Toronto home inspectors and many buyers. Properties with 100 amp service may face inspection flags or buyer concerns that affect negotiating position. Upgrading before listing or during renovation typically recovers its cost and removes a common buyer objection.
6. What does a 200 amp electrical service upgrade include?
A full service upgrade typically includes new service conductors from the utility connection to your property, a new meter base, an upgraded main disconnect, a new or expanded distribution panel, updated grounding and bonding, ESA permit, and final inspection. The scope may vary depending on your property’s existing
7. Can I keep my existing panel with a 200 amp service upgrade?
In some cases, an existing panel can be retained if it is in good condition and rated for 200 amp service. More commonly, an older panel is replaced as part of the upgrade since the panel is often the original bottleneck. Your electrician will assess the panel condition during the load calculation and recommend accordingly.
Ready to Upgrade? Book a Licensed Electrical Assessment
Phaze-In Electric Ltd. is a licensed, ESA-certified electrical contractor serving Toronto, North York, and the GTA. If you are not sure whether your property needs a service upgrade, our licensed Master Electrician will give you a clear load assessment, a transparent scope of work, and code-compliant installation from start to finish. Call or visit Phaze-In Electric Ltd to schedule your inspection.
Key Takeaways
- 200 amp electrical service is the standard for new construction in Toronto and provides double the capacity of a 100 amp service.
- Most Toronto properties with EV chargers, heat pumps, electric heating, or modern appliances benefit from upgrading to 200 amp service.
- Signs of an undersized service include frequent breaker trips, dimming lights when appliances start, and a full or aging panel.
- All electrical service upgrades in Ontario require an ESA permit and inspection — unlicensed work creates liability and insurance risk.
- A licensed Master Electrician should perform a load calculation before any service upgrade decision to confirm the right service size for your property.
- Phaze-In Electric Ltd. handles residential and commercial service upgrades across Toronto, North York, Etobicoke, Vaughan, Markham, Richmond Hill, Mississauga, and Oakville.
