Secondary suite permits in Toronto: forms, plans and fee

Check whether you need a permit

A building permit is needed for an interior alteration to add a second dwelling unit, smaller in area than the primary unit, in an existing Detached House, Semi-Detached House or Townhouse.
A common example of a secondary suite is a basement apartment.

Only if your project includes HVAC, plumbing, drain or water-service elements

If your project includes HVAC elements, review the Residential Mechanical (HVAC) Guide for additional requirements.
If your project includes plumbing or drain and water-service elements, submit a Plumbing Data Sheet with your Building Permit application.
For one- and two-unit houses, no plans are required unless the project includes a reverse-sloping driveway.
If the project includes a reverse-sloped driveway, then drawings must be submitted showing details of the reverse-sloped driveway and drain plan.
All other residential plumbing and drain permit applications must include drawings showing the layout of plumbing and related fixtures on each floor level.

The following forms are required as part of your submission package.

To submit an application for a building permit for a new secondary suite, all required forms and documentation may be submitted through Toronto Building Online Services Application Submission.
Once the application has been submitted, it will be assessed by our intake staff. If any required documentation is missing or incorrectly submitted, the applicant will be notified and the missing or incorrectly submitted documentation will need to be re-submitted.
If the application is submitted with all required documentation, it will be inputted into the City system and then an examiner will review the application as soon as possible.
When submitting your application online, you will have the option to submit your related mechanical, plumbing and drain permits once you have submitted your building permit application.
To submit an application by email, submit your required forms and documentation to bldapplications@toronto.ca.
Detailed steps for the email submission process are also available to assist in making your application.
The AI-assisted Building Permit Application Pre-Check is a voluntary tool that helps identify potential issues before you submit your application.
Please do not include any personal information on your Building Plans (e.g., the homeowner’s name or phone number).
Building Plans submitted for Permit are subject to disclosure in accordance with the Municipal Freedom of Information and Protection of Privacy Act (MFIPPA).

Fees effective January 1, 2026 (per m², unless otherwise stated):

Interior alterations (partitions, finishings, etc.), Group C, E and F: $11.53 per m² (≈ $1.07 per sq ft)
Residential Unit Fee: $56.33/unit for each new residential unit included in an application
The permit fees shown above are shown as a Service Index per square metre of proposed work, unless otherwise specified. For full details of permit fee calculation and a complete list of fee rates, please see the Building Permit Fees page.