Oshawa Secondary Suite Guide
Oshawa requires 11m lot frontage and 3 parking spaces for accessory apartments — check your lot before you start.
Permit Fees
Varies by project value — contact Oshawa Building
Timeline
3-5 months from application to occupancy
Region
Durham Region
Overview
Oshawa permits accessory apartments (basement apartments) in single detached and semi-detached dwellings in specific zones: R1, R2, R3, R5, OSR-A, OS-ORM, AG-A, AG-B, and AG-ORM. Your lot must have at least 11 m (36 ft) of frontage. Zones were expanded to include R3 in recent amendments.
If your second or third unit was created after July 1994, a building permit is required to legalize the use. Oshawa requires 3 parking spaces (2 accessible to the street at all times) and a 30-minute fire rating between units (less than the standard 1-hour in some configurations). The city is part of Durham Region, sharing regional services with Ajax, Pickering, and Whitby.
Oshawa Requirements
| Requirement | Standard | Notes |
|---|---|---|
Ceiling Height | 1.95 m (6'5") minimum | OBC standard applies. |
Fire Separation | 1-hour fire-rated assembly | 5/8" Type X gypsum both sides. Full assembly required. |
Egress Windows | 0.35 m² unobstructed opening per bedroom | Window wells for below-grade. No dimension less than 380 mm. |
Parking | 3 spaces minimum (2 accessible to street at all times) | This is one of the stricter parking requirements in the GTA. Tandem parking (one behind the other) may count if both are accessible. |
Electrical | Separate sub-panel + ESA permit | ESA inspection mandatory. |
Plumbing | Verify drain capacity + backwater valve | Backwater valve required in many cases. |
HVAC | Independent heating or zone control | Separate thermostat for accessory apartment. |
Zoning | R1, R2, R3, R5, OSR-A, OS-ORM, AG-A, AG-B, AG-ORM zones | R3 added in recent amendments. Minimum 11 m (36 ft) lot frontage required. Single detached and semi-detached only. |
Ontario Building Code Standards (Apply Everywhere)
These OBC requirements apply to all secondary suites in Ontario, regardless of municipality.
Fire Separation: 1-hour fire-rated ceiling assembly (Type X drywall)
Required between dwelling units. 2024 OBC update: smoke-tight barriers may replace full fire separations in some configurations. Inspected before occupancy permit.
Egress Windows: Min 0.35 m² openable area per bedroom
Bottom of opening max 1.5 m above floor. Must be rescuable from outside.
Electrical: Separate 100A panel minimum
ESA inspection mandatory. AFCI breakers required for bedrooms.
Plumbing: Separate water meter + backwater valve
Drainage must meet Part 7 standards. Backflow prevention required.
HVAC: Independent heating system OR zone control
Ventilation: min 10 L/s per occupant. HRV recommended.
Permit Process
Step-by-step guide to getting your Oshawa building permit
Total Timeline
3-5 months from application to occupancy
Permit Fees
Varies by project value — contact Oshawa Building
Verify Zoning
1-2 daysConfirm your property is in R1, R2, R3, R5, OSR-A, OS-ORM, AG-A, AG-B, or AG-ORM zone. Check lot frontage is at least 11 m.
Prepare Drawings
1-3 weeksFloor plans, sections, fire separation details, plumbing, electrical, HVAC. Show 3 parking spaces on site plan.
Submit Building Permit
1 daySubmit to Oshawa Building Department.
Plan Review
4-8 weeksCity reviews for OBC, zoning, and fire code compliance.
Construction + Inspections
8-12 weeksBuild per approved plans. Inspections at framing, insulation, electrical, plumbing, final.
Final Approval
1-2 weeksAll inspections pass, receive certificate of occupancy.
Incentives & Rebates
Federal and provincial programs that can help fund your secondary suite project. See all rebates available in Oshawa
Canada Secondary Suite Loan
Up to $80,000 at 2% interest
Federal loan program. 15-year repayment.
Ontario Secondary Suite Incentive
Up to $40,000 forgivable
Rent at below-market rates for 5 years — loan forgiven at 20% per year.
Pro tip: You can stack federal and provincial programs for up to $120,000 in combined funding. Apply for federal programs first, then provincial.
Oshawa-Specific Tips
- Limited to specific zones: R1, R2, R3, R5, OSR-A, OS-ORM, AG-A, AG-B, AG-ORM. R3 added recently. Check your zoning before investing in drawings.
- Minimum lot frontage: 11 m (36 ft). Narrow lots may not qualify.
- 3 parking spaces required with 2 accessible to the street at all times.
- Units created after July 1994 need a building permit to be legalized — if your existing apartment was never permitted, start the legalization process now.
Official Resources
Secondary Suite Guides for Nearby Cities
Compare requirements and incentives in other Ontario municipalities.
Related Services
Common trades and services for basement apartment projects.
Complete Guide
Province-wide secondary suite guide with all requirements.
Learn moreUnderpinning
Excavate to lower floor and meet ceiling height requirements.
Learn moreWaterproofing
Fix moisture issues before finishing basement apartment.
Learn moreElectrical
Panel upgrades, separate meters, and ESA permits.
Learn morePlumbing
Drain capacity, backwater valves, and separate water meters.
Learn moreCommon Questions
Get a Quote for Your Oshawa Basement Apartment
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