Permission first. Construction second.
Halton Hills adopted Additional Residential Units zoning amendment 2024-0098 on December 9, 2024. The official bylaw register supports adoption; actual parcel eligibility still depends on mapped zoning and later amendments. The right answer still depends on your property and the proposed dwelling form.
What may be allowed
On an eligible fully serviced residential property, the Town allows a principal dwelling plus up to two additional residential units. They may both be within the main dwelling, or one may be inside and one in an accessory building. The Town says the usual additional-unit size limit is the lesser of 40% of the applicable dwelling area or 110 m², with a basement exception. These limits do not settle a particular lot’s eligibility.
Not a parcel approval. This is a city-level planning summary; a zoning, servicing and building-permit review is still needed for your specific address.
What to check before planning construction
- Confirm the property’s current land-use zone and whether that zone permits the proposed ARU form.
- Check water/wastewater servicing and whether special rural requirements apply.
- Review on-site parking; the Town’s published guidance calls for two spaces for the main unit plus one per ARU.
- Apply for building approvals and complete the Town’s ARU registration before occupancy.
Which rules govern?
The Town identifies Zoning By-law 2010-0050 as amended by By-law 2024-0098 and separate ARU registration requirements under By-law 2023-0060. Do not assume provincial ARU permissions override every local property restriction.
Next step
Check the property’s zoning and servicing status with Halton Hills Planning or Building Services before paying for design work. You can also review the official verification steps or browse other Ontario city guides.
Nearby guide: Milton.
Municipal evidence check · October 12, 2026
Confirmed for this claim: Halton Hills’ official bylaw register records adoption of ARU amendment 2024-0098 on December 9, 2024. This confirms bylaw identity and adoption, not unrestricted ARU permission on every parcel.
Still to verify: Check consolidated 2010-0050 zoning schedules and later amendments, mapped zoning, servicing and lot-level restrictions.
This is a targeted official-source review, not complete certification of every adopted amendment or approval for your property.
How this guide was verified
Guide verification: Targeted municipal-source claim check recorded. This guide provides linked municipal research; a complete enacted-bylaw, zoning-map and amendment cross-check has not been documented for this municipality.
Property confidence: Not assessed. City-wide guidance does not confirm permission for a particular parcel. Check official zoning, overlays and permits. How verification works →
Official sources
- Halton Hills adopted Bylaw 2024-0098
- Halton Hills confirmation: now in effect
- Halton Hills — additional residential units and registration ↗
Reviewed 9 October 2026. Municipal guides describe published rules only. Source consolidations may not include the latest adopted amendment. No site-specific approval is represented.
Targeted primary-source evidence checked October 12, 2026 (municipal link above).