An Additional Residential Unit (ARU) is a self‑contained living space added to an existing home or property. This could be a basement apartment, a unit within your house, or a small detached unit on the same lot as your primary residence.
Up to four total units are permitted on a fully serviced lot/or on a lot serviced by both municipal water and wastewater, and three units in an area serviced by a septic system and/or well, as long as zoning requirements are met. Each ARU must include its own kitchen, bathroom, sleeping area, and a separate entrance.
Middlesex Centre supports ARUs as a practical way to create more housing options and make better use of existing homes, while helping address long‑term housing needs in our community.
If you’re thinking about adding additional units to your property, our Additional Residential Units (ARU) Guide walks you through what’s allowed, what approvals you’ll need, and what to expect along the way:
Additional Residential Units (ARU) Guide
You may also be eligible for financial support through Middlesex Centre’s Community Improvement Plan (CIP), which offers funding to help offset some of the costs associated with creating an ARU.
Related Webpages
- Building Services
- Planning & Development Services
- Housing Accelerator Fund (HAF)
- Community Improvement Plan (CIP)
Additional Resources
- Adding a Second Unit in an Existing House Guide (Ministry of Municipal Affairs and Housing)
- Additional Residential Unit (ARU) Overview (Middlesex Centre)
Questions
If you have any questions about ARUs, please contact Middlesex Centre Planning & Development Services or Building Services.