Accessory dwelling units (ADUs) are self-contained living spaces on a property that already has a primary dwelling. In Ottawa, ADUs include: Secondary dwelling units: Typically basement apartments or units within the existing house. Most common and least expensive to create ($50,000–$100,000). Coach houses: Detached dwelling units on the same property, often above a detached garage or as a standalone structure. More expensive ($150,000–$300,000) but offer greater privacy and independence. Gar...
The City of Ottawa's zoning by-law specifies where ADUs are permitted and their requirements: Secondary dwelling units: Permitted in most residential zones (R1–R5). Maximum one per property. Must have a separate entrance, meet Ontario Building Code requirements, and comply with parking minimums. Coach houses: Permitted in many residential zones, subject to: maximum gross floor area (often 45–70 sq m depending on zone), maximum height (typically 5–6.5m), setback requirements from property lines...
The permit process for ADUs involves multiple steps: 1. Zoning verification: Confirm your property allows the type of ADU you want. If it doesn't, a rezoning application or minor variance may be needed ($1,500–$5,000, 2–6 months). 2. Site plan: For coach houses, a site plan approval may be required ($1,000–$3,000 application fee, 2–4 months). Secondary dwelling units typically don't require site plan approval. 3. Building permit: Required for all ADUs. Includes architectural drawings, structu...
Secondary dwelling unit (basement apartment): $50,000–$100,000. Includes separate entrance, kitchen, bathroom, bedroom, fire separation, and all mechanical systems. Generates $1,200–$2,000/month in rental income. Coach house over detached garage: $150,000–$250,000. Includes foundation/structure, full living unit, separate services, and landscaping. Generates $1,500–$2,500/month in rental income. Standalone coach house: $200,000–$350,000. A fully detached dwelling unit. Includes foundation, con...
Designing an ADU for Ottawa's climate requires attention to energy efficiency, durability, and livability: Insulation: ADUs must meet Ontario Building Code energy requirements. For above-grade units, R-24 walls and R-50 roof insulation are minimum. For basement units, spray foam on foundation walls is recommended. Heating and cooling: Ductless mini-splits are the most popular HVAC solution for ADUs. They provide independent heating and cooling without connecting to the main house's system. Cos...
Many Ottawa residential zones now permit coach houses. Check your specific zone at GeoOttawa. Requirements include maximum size, height, and setback compliance. Site plan approval may be required.
Basement apartments: $50,000–$100,000. Coach houses: $150,000–$350,000. Professional fees add $10,000–$25,000. ROI through rental income typically provides payback in 3–10 years.
Secondary dwelling units: 3–6 months for permits. Coach houses: 6–12 months including potential site plan approval. Add construction time of 3–6 months for basement units, 6–12 months for coach houses.
Most zones require one parking space per dwelling unit. Properties near LRT stations may have reduced requirements. Verify your zone's specific parking requirements before designing your ADU.
Yes. Adding a legal dwelling unit increases your property's assessed value and therefore your property taxes. The tax increase is typically modest compared to the rental income generated — usually $1,000–$3,000/year in additional taxes.