Short answer
Oakville uses comprehensive Zoning Bylaw 2014-014 and its amendments, including changes noticed in 2026.
What local rules actually say
Additional residential units are addressed by the town’s current zoning framework. A permitted ARU inside or alongside a detached, semi-detached or townhouse-type residence must be distinguished from a purpose-built duplex/fourplex with different standards.
Important exceptions and the next step
Check the parcel’s zone, any mature-neighbourhood or heritage overlay and the updated additional-unit provisions; the 2026 amendment does not itself certify an entitlement on every lot.
How to verify an individual property
- Look up the legal property address and zone on the official Oakville zoning map.
- Confirm the proposed dwelling type: internal suite, addition, detached garden home or multiplex; these can follow different rules.
- Verify zone exceptions, lot size, servicing, hazard/heritage limits, any registered restrictions and the current amending bylaws.
- Ask the local planning/building office for the required written zoning confirmation and building permits before commissioning construction.