Project capacity guide
Do you need 200 amps for a secondary suite?
Electrical-capacity planning for a secondary suite at home.
Short answer
A secondary suite does not automatically require 200A service. The decision depends on suite cooking, laundry, water heating, space heating, metering and the total dwelling load.
Key takeaways
01Start with equipment specifications and the home’s current demand.
02Panel space does not prove service capacity.
03The project should be assessed before equipment is purchased or installation is booked.
What determines capacity
The contractor needs to review suite cooking, laundry, water heating, space heating, metering and the total dwelling load. The applicable calculation and local permit rules determine the acceptable design.
Alternatives to a service increase
retaining one service may be possible only when the calculation and local requirements support it. Any alternative still needs to be approved for the equipment, installation and jurisdiction.
What to prepare
Bring the equipment model or expected rating, service-size clues, existing major loads, panel-space information and future project plans.
Field notes / decision evidence
Count both living areas
A suite changes the home as a system. Metering and the appliance schedule should be reviewed alongside the service.
Suite appliance plan
List cooking, laundry, water heating and space heating in the suite and the main home. Identify which equipment is existing and which is planned.
Shared or separate
Ask whether the project uses one service, a separate meter or another approved configuration. The utility and local authority determine the path.
Permit package
Have the contractor identify the suite load calculation, City permit requirements and any ENMAX service request before work is scheduled.
Illustrative scenarioExample only: a small suite with gas heat and a suite with electric heat can present different demand even when their floor area is similar.
Decision table
What the evidence changes
- Automatic 200A requirement
- No
- Decision evidence
- Applicable load calculation + equipment information
- Possible paths
- Existing service, distribution change, management or service upgrade
Typical project sequence
From question to documented work
- 01Choose equipment concept
- 02Check existing service and loads
- 03Complete calculation
- 04Confirm permit / utility path
- 05Install and inspect
Sequence and responsibilities vary by jurisdiction, utility and scope.
Evidence
Sources and verification
Published by the 200AmpPanel.ca Research Team, a HAUSE specialist property. Updated 2026-09-29.
Questions
Frequently asked
Can a 100A home support a secondary suite?
Sometimes. The service size alone cannot answer; existing demand and project design matter.
What should I do next?
Use the Capacity Check to organize what you know, then have a qualified electrical contractor complete the assessment required for the property and jurisdiction.
Your next step
Bring the right facts to the first conversation.
Record the visible service clue, planned equipment and any relevant documents. The free brief organizes your questions; a qualified person verifies capacity and scope.