Ottawa's SDU (Secondary Dwelling Unit) permit process is documented but confusing. This guide walks you through every step from pre-application to occupancy permit, with 2026 timelines and costs.
Before any design work, confirm your lot zoning permits an SDU. Ottawa allows SDU in most R1, R2, R3, R4 zones as-of-right. Pull your zoning at ottawa.ca/zoning or call 3-1-1. Check: lot size minimum, lot width minimum, current dwelling-unit count (some lots are at max already), and any overlay zones (heritage, flood plain). If non-conforming, you may need a Minor Variance ($1,200-$2,500, 4-6 months).
Design must meet OBC 9.36 for energy + 9.10.9.14 for fire separation between units. Engage BCIN-qualified designer ($3K-$8K for typical basement SDU) or architect ($8K-$25K for new garden suite). Drawings required: floor plans, elevations, cross-section, mechanical, electrical, plumbing layouts. Allow 4-10 weeks for design depending on complexity.
Apply through City of Ottawa permit portal. Submit: stamped drawings, scope letter, site plan (showing lot lines/setbacks/existing buildings), HVAC heat-loss calc (for new SDU), and permit fee ($1,800-$5,500 typical). Plan review takes 4-8 weeks for typical residential SDU. Reviewers may request revisions; budget 2-3 review cycles. Avoid: incomplete submissions (auto-rejected and re-queued).
Electrical Safety Authority (ESA): separate permit for any new wiring or panel work ($150-$485). Plumbing permit through City of Ottawa for any plumbing changes ($150-$385). HVAC permit ($150-$485). These can be applied for after building permit issuance or in parallel. Each trade contractor pulls their own permit.
Required inspections (typical sequence): (1) Footings/foundation (if new). (2) Structural framing. (3) Rough plumbing. (4) Rough electrical (ESA). (5) Insulation/vapour barrier. (6) Final framing/drywall close-in. (7) Fire separation (sound + flame between units). (8) Final building inspection. (9) Final electrical (ESA). (10) Final plumbing. (11) Occupancy permit. Each inspection: schedule 3-5 days in advance through City of Ottawa portal. Failed inspections require re-inspection ($150-$250 fee...
Final occupancy permit issued after all inspections pass + fire separation verified + smoke/CO alarms confirmed interconnected. Without occupancy permit, renting the unit is illegal and exposes you to insurance claim denial + bylaw fines. Typical total SDU timeline: 6-14 months from zoning check to occupancy permit, depending on whether design + permit + construction proceed without major issues.
Zoning + design: 4-12 weeks. Building permit review: 4-8 weeks. Construction: 14-32 weeks for typical basement SDU; 22-44 weeks for new garden suite. Final inspections + occupancy permit: 2-4 weeks. Total typical timeline: 6-14 months from start to occupancy permit.
Building permit $1,800-$5,500. ESA electrical $150-$485. Plumbing $150-$385. HVAC $150-$485. Designer/architect $3K-$25K. Total permit + design soft costs: $5K-$32K depending on scope (basement SDU vs new garden suite).
Not for basement SDUs under 600 sq ft — a BCIN-qualified designer is sufficient ($3K-$8K). For new garden suites or coach houses, or any SDU over 600 sq ft / 200m² gross floor area, an Ontario-licensed architect or BCIN-qualified designer is required to stamp drawings.
Ontario Building Code 9.10.9.14: 1-hour fire-resistance separation between dwelling units. Includes: 5/8" Type X drywall on both sides of separating wall with proper insulation and sealed penetrations, self-closing fire-rated doors, interconnected smoke alarms, and 30-minute fire-rated ceiling assembly between floor units.
Yes — Ottawa SDU rules don't dictate which unit you live in. You can occupy the upper unit and rent the basement SDU, or vice versa. You can also rent both units (owner doesn't have to occupy either).