What are the ARU rules in Kingston?
Kingston allows up to four units per lot in low-rise residential areas, including attached, detached, garage and basement ARUs. An ARU can be as large as the main house and needs one parking space. The City offers forgivable loans of up to $40,000, now waitlisted.
| Rule | What it says | Source |
|---|---|---|
| Units per lot | Up to 4 in low-rise residential areas (Council approval July 9, 2024). ARUs are not permitted on rural properties. | Official source |
| ARU types | Attached, detached, converted garage, interior or basement | Official source |
| Maximum size | ARU gross floor area equal to or less than the main dwelling | Official source |
| Parking | At least 1 space, tandem allowed | Official source |
| Not permitted | Lots with 2+ units already, a garden suite, boarding or lodging house. No basement ARUs in sewer surcharging areas. Excluded: sewer capacity limit areas, Loughborough Lake, natural hazard lands | Official source |
| Zoning bylaw | Zoning By-law 2022-62 | Official source |
| Development charges | Exempt for 2nd and 3rd units and for intensification of existing housing (2026 DC pamphlet) | Official source |
Servicing: Lots with an old half-inch water service may need an upgrade, partly covered by a City grant. Lots in Water Supply or Cana Subdivision servicing areas need a holding symbol removed first. (source)
These local rules sit on top of Ontario's province-wide ARU rules. See how Kingston compares in our ARU rules by city comparison.
How do I get an ARU building permit in Kingston?
Apply online through the DASH portal with a plot plan, floor plans, elevations and sections, spatial separation, mechanical and energy details and a designer form. The City aims to issue or request more information within 10 business days. Book inspections in DASH with 24 hours notice. Existing unpermitted units must be legalized.
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 Kingston?
In Kingston, the best local incentive right now is: Up to $40,000 forgivable loan (waitlisted). 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 |
|---|---|---|---|
| Detached ARU Incentive | Lesser of 50% of cost or $40,000 | Forgivable loan over 5 years. Rent capped at 90% of average market rent to an income-eligible tenant | Waitlisted. Permit must be issued by Dec 1, 2026 |
| Interior ARU Incentive | Lesser of 50% of cost or $30,000 | Same terms as the detached incentive | Waitlisted |
| Accessibility ARU Grant | $5,000 | Meets accessibility criteria such as 900 mm doors and 1100 mm halls. Stacks with the above | Waitlisted |
| Rough-In Detached ARU Grant | $5,000 | Water, sewer and electrical rough-ins for a future detached ARU. Cannot be combined | Waitlisted |
| Servicing Constraint Area Grant | Lesser of 50% or $10,000 | Upgrade of a half-inch water service, combined with a detached or interior incentive | Waitlisted |
Full conditions, rent caps and the application steps are in our Kingston ARU incentive program guide.
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 Kingston?
A 2 bedroom in Kingston rents for about $1,764 a month on average, and a 1 bedroom about $1,503 (Kingston CMA, 2026). Vacancy: 2.4% (2025). A new, private suite with its own entrance often rents above these averages, which cover existing rental units.
Source: City of Kingston 2026 average market rent table; CMHC 2025 vacancy.
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 (30 nights or less) need a City licence, currently $203, and Municipal Accommodation Tax applies. Secondary suites in single-detached homes can qualify. Incentive-funded units must be long-term rentals at capped rent. Official rules
Are there pre-approved ARU designs in Kingston?
Pre-reviewed detached ARU designs (Building Code only, not zoning) are listed by the City from three vendors: Brauer Housing, First Capital Construction and Redden’s Contracting. A permit is still required. See the designs.
Worth knowing
- 89 ARU building permits were issued in 2025 up to November 30.
- Kingston CMA vacancy was 2.4% in 2025, and only 1.2% for 3+ bedroom units.
- Kingston signed a $27.6M Housing Accelerator Fund agreement in January 2024 that commits to four units as of right.
Who do I call in Kingston?
Start with the City of Kingston building or planning office for zoning and permit questions. These numbers come from the municipality's own website.
| Office | Contact |
|---|---|
| Building Services | 613-546-4291 ext. 3280 |
| Permit email | buildingpermits@cityofkingston.ca |
| Incentives (Housing) | housing@cityofkingston.ca |
Or skip the phone tag: send us your address and we will check the Kingston rules against your lot for free. Book a free property check.
Kingston secondary unit FAQ
How many units can I have on my lot in Kingston?
Kingston approved up to four units per lot in low-rise residential areas in July 2024. ARUs are not permitted on rural properties, or on lots that already have two or more units or a garden suite. Confirm your zone under By-law 2022-62 before you design.
How big can an ARU be in Kingston?
The ARU can have a gross floor area equal to or less than the main house. Height, setbacks and lot coverage come from your zone and the accessory building rules, so the real maximum depends on the lot.
Do I pay development charges on a Kingston ARU?
Usually not. Kingston’s 2026 development charge pamphlet exempts second and third units and intensification of existing housing, in line with the provincial exemption.
Sources
Checked October 26, 2026. Rules change; confirm with the municipality before you apply. We are builders, not planners or lawyers.
- City of Kingston: Additional Residential Units
- City of Kingston: ARU permits
- City of Kingston: ARU incentive programs
- City of Kingston: Pre-reviewed detached ARUs
- City of Kingston: 2026 development charges pamphlet
- City of Kingston: 2025 rental market news
- City of Kingston: Short-term rental licensing