What are the ARU rules in Cobourg?
Cobourg’s 2025 zoning bylaw allows two ARUs with a single, semi or townhouse, so three units in total, with one allowed in a detached building. An ARU can be 50% of the main home, or the whole basement. Town and County programs can add up to $20,000 or more.
| Rule | What it says | Source |
|---|---|---|
| Units per lot | Up to 2 ARUs with a single, semi or street townhouse (3 total). Both in the house, or 1 in the house and 1 detached | Official source |
| Maximum size | 50% of the primary unit’s GFA, except a basement ARU can use the whole basement. Detached: 50% of the main home, max 50% of the rear yard | Official source |
| Height and separation | Detached ARU up to 4.5 m, or 8.0 m above a garage on a lane. At least 4.5 m from the main building | Official source |
| Not permitted | Environmental Constraint zone, floodplain, or lots with shared housing, a B&B or a group home | Official source |
| Zoning bylaw | Comprehensive Zoning By-law 066-2025, passed December 17, 2025 | Official source |
| Development charges | ARUs exempt under DC By-law 058-2025. New single home pays $29,115 to $49,338 depending on area | Official source |
Servicing: Where municipal services are available, ARUs must connect to them. (source)
These local rules sit on top of Ontario's province-wide ARU rules. See how Cobourg compares in our ARU rules by city comparison.
How do I get an ARU building permit in Cobourg?
Apply through Cloudpermit. Staff review plans and inspect on site. ARUs must connect to municipal services where available.
Permit-ready drawings are where most delays start. Our ARU design and permit service prepares the full set and answers reviewer comments.
Are there grants for secondary units in Cobourg?
In Cobourg, the best local incentive right now is: Up to $20,000 County loan + Town CIP. Second and third units are also exempt from development charges, and the federal CMHC-insured refinance lets owners borrow up to 90% of the finished home's value. Check each program's status below before you plan around it.
| Program | Amount | Conditions | Status |
|---|---|---|---|
| Northumberland Affordable Housing Grant | Up to $20,000 per unit, forgivable | Owner lives in the main home, affordable rent for 25 years (2026 caps: 1 bed $1,500, 2 bed $1,750), tenant income limits, no short-term rental | Program page live, no deadline posted |
| Cobourg CIP: Second Unit Renovation and Construction Grant | Up to $10,000 or 50% of cost | Owner-occupied sole and primary residence | Confirm intake with the Town |
| Cobourg CIP: Second Unit Loan | Up to $50,000 | Owner-occupied sole and primary residence | Confirm intake with the Town |
| Cobourg CIP: Planning and Building Fee Reduction | 100% of specified fees | Pre-consult with Planning | Confirm intake with the Town |
Federal options apply everywhere, including CMHC-insured refinancing of up to 90% of the finished home's value. Read the secondary suite financing guide.
What rent can a secondary unit earn in Cobourg?
A 2 bedroom in Cobourg rents for about $1,650 a month on average, and a 1 bedroom about $1,400 (Northumberland County, Program benchmark). Vacancy: not published. A new, private suite with its own entrance often rents above these averages, which cover existing rental units.
Source: Northumberland County average market rent benchmarks (not CMHC).
Averages for existing rental units. A new, private suite often rents above the average. Data source.
Can I use the unit as a short-term rental?
Short-term rentals need a Town licence through Cloudpermit. 2026: $150 to apply, $500 for a Class A licence, plus fire and electrical inspections. County-funded units cannot be short-term rentals. Official rules
Worth knowing
- A basement ARU can take up the entire basement, an exception to the 50% cap.
- A detached ARU above a lane garage can be 8.0 m tall.
- Cobourg joined the Canada-Ontario Partnership to Build program in June 2026, which requires 30 to 50% DC reductions.
Who do I call in Cobourg?
Start with the Town of Cobourg building or planning office for zoning and permit questions. These numbers come from the municipality's own website.
| Office | Contact |
|---|---|
| Planning | 905-372-1005 |
| Town main line | 905-372-4301 |
| County Housing Services | 1-800-354-7050 |
Or skip the phone tag: send us your address and we will check the Cobourg rules against your lot for free. Book a free property check.
Cobourg secondary unit FAQ
How many units can I add in Cobourg?
Under Zoning By-law 066-2025, you can add two ARUs to a single, semi or street townhouse, for three units in total. Both can be in the house, or one in the house and one in a detached building. Two ARUs cannot share one detached building.
How big can an ARU be in Cobourg?
An ARU can be up to 50% of the main unit’s gross floor area. A basement ARU can use the whole basement. A detached ARU is limited to 50% of the main home and 50% of the rear yard, with no habitable space below grade.
What grants are there for ARUs in Cobourg?
Northumberland County offers forgivable loans of up to $20,000 per unit for 25 years of affordable rent. The Town’s Community Improvement Plan has offered second unit grants up to $10,000, loans up to $50,000 and fee rebates. Confirm the current intake with each.
Sources
Checked October 26, 2026. Rules change; confirm with the municipality before you apply. We are builders, not planners or lawyers.
- Town of Cobourg: Comprehensive Zoning By-law 066-2025
- Town of Cobourg: Notice of passing of zoning bylaw
- Town of Cobourg: DC By-law 058-2025
- Town of Cobourg: Affordable housing CIP
- Northumberland County: Affordable Housing Grant Program
- Town of Cobourg: Short-term rental accommodations
- Town of Cobourg: Building and renovating