Ajax Secondary Suite Guide
Ajax offers the Build More, Get More Grant and a new e-permitting portal — making secondary suites easier than ever.
Permit Fees
Varies by project value — check e-permitting portal
Timeline
3-5 months from application to occupancy
Region
Durham Region
Overview
Ajax permits accessory apartments in eligible dwellings with specific size limits: minimum 25 m² (269 sq ft) gross floor area, and the apartment cannot exceed the ground floor area of the main dwelling. Houses less than 5 years old face stricter Part 9, Division B OBC requirements.
The town launched its e-permitting portal (eapply.ajax.ca) in April 2025, reducing approval timelines. Ajax also offers the Build More, Get More Grant Program for new additional dwelling units.
Ajax Requirements
| Requirement | Standard | Notes |
|---|---|---|
Ceiling Height | 1.95 m (6'5") minimum | OBC standard. Houses less than 5 years old reviewed under stricter Part 9 Division B requirements. |
Fire Separation | 1-hour fire-rated assembly | Type X drywall both sides. Newer homes (<5 years) may have additional fire separation requirements under Part 9 Division B. |
Egress Windows | 0.35 m² unobstructed opening per bedroom | No dimension less than 380 mm. Below-grade bedrooms need window wells. |
Parking | Check Ajax zoning by-law | Requirements vary by zone. Contact Ajax Building Department. |
Electrical | Separate sub-panel + ESA permit | ESA inspection mandatory for all electrical work. |
Plumbing | Verify drain capacity + backwater valve | Backwater valve recommended. Verify fixture unit count. |
HVAC | Independent heating or zone control | Separate thermostat required for accessory apartment. |
Zoning | Min 25 m² floor area, max = ground floor area of main dwelling | Accessory apartment cannot be larger than the primary dwelling's ground floor. |
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 Ajax building permit
Total Timeline
3-5 months from application to occupancy
Permit Fees
Varies by project value — check e-permitting portal
Check Eligibility
1-2 daysVerify your property is eligible. Minimum 25 m² apartment, cannot exceed ground floor area of main dwelling. Houses under 5 years old face stricter OBC Division B requirements.
Prepare Drawings
1-3 weeksHire a designer for floor plans, sections, and details. Show fire separation, egress, plumbing, electrical, and HVAC compliance.
Submit via e-Permitting
1 daySubmit application through Ajax's e-permitting portal at eapply.ajax.ca (launched April 2025). Upload drawings and pay fees online.
Plan Review
4-8 weeksAjax reviews for OBC, zoning, and fire code compliance.
Construction + Inspections
8-12 weeksBuild per approved plans. Call for inspections at framing, insulation, electrical, plumbing, and final.
Occupancy
1-2 weeksAll inspections pass, receive occupancy permit.
Incentives & Rebates
Federal and provincial programs that can help fund your secondary suite project. See all rebates available in Ajax
Build More, Get More Grant
$4,000 per unit, max $12,000
Ajax cash-back grant for new additional dwelling units — basement apartments, garden suites, and garage conversions. Up to 3 units eligible per property.
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.
Ajax-Specific Tips
- Houses less than 5 years old face stricter Part 9 Division B OBC requirements — more restrictive construction standards.
- Apartment size limits: minimum 25 m² (269 sq ft), maximum cannot exceed ground floor area of the main dwelling.
- Ajax launched e-permitting (eapply.ajax.ca) in April 2025 — submit applications and track progress online.
- Build More, Get More Grant available for new ADUs — check with Ajax for current funding and eligibility.
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 Ajax Basement Apartment
Connect with verified contractors who specialize in secondary suite construction. Escrow-protected payments, GPS-verified work, and permanent records.