Additional Residential Units Guide

SERVICE ANNOUNCEMENT: Bill 23 and Additional Residential Units
New Regulations for Additional Residential Units

Please note that the City’s requirements for Additional Residential Units (previously known as Secondary Suites) have changed effective August 28, 2023 pursuant to By-law 23-087. 

Bill 23, More Homes Built Faster Act, 2022 was introduced by the Province on October 25, 2022. Third reading and Royal Assent was granted on November 28, 2022. The new legislation makes amendments to nine different statutes, including the Conservation Authorities Act, the Municipal Act, 2001, the Ontario Heritage Act, the Ontario Land Tribunal Act, 2021, and the Planning Act. The associated regulations relating to additional residential units came into force on December 23, 2022.

With the intention of increasing the supply of housing, the Province introduced changes to the Planning Act to allow gentle density/intensification by requiring municipal zoning to permit ‘gentle intensification’ of up to 3 units per lot (up to two in the main building and one in an accessory building or up to three in the main building) in a detached, semi-detached or townhouse dwelling; prohibiting municipal zoning to regulate minimum unit size or from requiring more than one parking space per unit for ‘gentle intensification’ units; and exempting ‘gentle intensification’ units from Development Charges, Parkland and Community Benefit contributions.

Printable version of the New Additional Residential Units Guide

A printable copy of the New Additional Residential Units (ARUs) Guide is available online in an Adobe PDF format.

What is an Additional Residential Unit (ARU)?

An ARU is a self-contained residential unit with a private kitchen, bathroom facilities and sleeping areas within dwellings or within structures ancillary to a dwelling. Additional Residential Units are also referred to as second units, basement apartments, accessory apartments, granny flats, in-law apartments or nanny suites

Why Additional Residential Units?

The City of Peterborough is permitting the creation of ARUs to achieve the following objectives:

  • To provide housing for a variety of users including aging family members, adult children, caregivers etc.
  • To increase the supply of rental housing and improve rental affordability
  • To alleviate the cost of homeownership
  • To make efficient use of infrastructure, housing stock, land and resources
  • To facilitate residential intensification, mitigate climate change, and reduce greenhouse gas emissions

Building a new Additional Residential Unit

Please visit our Building a New Additional Residential Unit page to see Zoning By-law requirements associated with new ARUs.

Existing Additional Residential Units

If you have an existing ARU, please visit our Legalizing Existing Additional Residential Units page to ensure your ARU meets applicable regulations.

Obtaining a Building Permit

If your property meets requirements for an ARU, please visit our Obtaining Your Building Permit page to see information about requirements under the Ontario Building Code.