Secondary Suites Guide - Obtaining Your Building Permit

This building permit guide for secondary suites is intended to familiarize homeowners and their contactors with general requirements set out by the Ontario Building Code, and applicable law to help assist in obtaining a building permit for construction of new or conformity of existing secondary suite. 

Sections below outline general submission requirements such as types of documents and drawings necessary for review of a secondary suite construction, as well as, comprehensive requirements applicable to the construction of living spaces and safety requirements such as fire prevention.

Submission Requirements

1. Completed Building Permit Application Form
2. Two (2) sets of drawings/plans:
   • Drawn to scale and printed in ink
   • Fully dimensioned either in metric or imperial, but not in combination
   • Must include:
     • Site Plan
     • Existing Floor Layouts
     • Proposed Floor Layouts
     • Cross Sections and Wall/Ceiling/Fire Separation Construction Details
     • Elevations showing Secondary Suite Entrance and Egress Window
     • HVAC and mechanical drawings

Homeowners are permitted to prepare plans however the City of Peterborough recommends that drawings be prepared by a professional such as an engineer, architect, or a designer with a Building Code Identification Number (BCIN)

Construction & Safety Requirements

Table Note: The date of existence of a house is the date after the house permit has been issued, work has commenced and the first inspection has taken place. 

General Design Requirements

• Carbon Monoxide alarms are required adjacent to each sleeping area
• Each unit shall have access to common laundry facilities or have connections within each unit for the connection of laundry appliances
• Minimum required dwelling unit size is 30 m² and meet minimum room sizes as per Ontario Building Code requirements

• Exterior access to Additional Residential Units/Secondary Suites shall:
  • be clear and unobstructed (including utilities protruding from the building);
  • be constructed of a hard and stable surface;
  • minimum width of no less than 0.9m;
  • cross-fall: 2% min - 5% max;
  • longitudinal slope 2% min – 8% max;
  • wherever feasible, stairs shall be avoided;
  • drainage function of swales, typically located on properly lines, shall be maintained;
  • external pass-through sheet drainage across access walkways are not permitted;
  • where minimum access requirements are shared across properly lines between multiple properties, registered easements on title shall be required.

Note: This design advice does not cover all requirements for secondary suites.  It is the designer’s responsibility to ensure compliance with the current Ontario Building Code.  A copy of the Ontario Building Code (Ontario Regulation 332/12 made under the Building Code Act, 1992) is available online through the e-Laws website.

Building Permit Requirements: Sample Site Plan

General Design Requirements

Disclaimer: The design examples, including sample drawings, in this guide are not advice nor do they address all the requirements for legally establishing a secondary suite. It is each property owner’s responsibility to ensure compliance with all current applicable law, including the Ontario Building Code, the City’s Comprehensive Zoning By-law and any other provisions or regulations applicable to secondary suites. A copy of the Ontario Building Code (Ontario Regulation 332/12 made under the Building Code Act, 1992) is available online through the e-Laws website.

• A copy of the City’s Comprehensive Zoning By-law is available online through City of Peterborough’s website