How much does it cost to build a secondary suite?

Secondary Suite Costs in Ottawa

Building a secondary suite in Ottawa typically ranges from $80,000 to $200,000, depending on the size, location within your home, and finish level. This wide range reflects the complexity and customization involved in creating a legal, code-compliant rental unit.

The cost breakdown generally includes several major components. Structural work and permits often account for $15,000-$30,000, covering building permits ($2,000-$5,000), structural modifications, fire separations, and separate entrance creation. Mechanical systems including electrical, plumbing, and HVAC upgrades typically run $20,000-$40,000, as secondary suites require separate utilities and enhanced ventilation systems per Ontario Building Code requirements.

Kitchen and bathroom installation represents another significant expense at $25,000-$50,000 combined. Even a basic secondary suite kitchen with essential appliances and modest finishes starts around $12,000, while bathrooms range from $8,000-$20,000 depending on size and fixtures. Flooring, drywall, insulation, and finishing work generally adds $20,000-$40,000 to the total project cost.

Ottawa-Specific Considerations

In Ottawa, secondary suites must comply with R4 zoning requirements and specific size minimums - bachelor units need at least 28 square meters, while one-bedroom units require 37 square meters. The 45-minute fire separation between units is mandatory and affects both timeline and budget. Most Ottawa homes built before 1990 require electrical panel upgrades to support the additional unit, adding $3,000-$8,000 to costs.

Basement conversions typically fall on the lower end of the range ($80,000-$120,000) since the basic structure exists, while above-grade additions or major reconfigurations can easily exceed $150,000. Properties in older Ottawa neighborhoods often face additional challenges with outdated electrical systems, inadequate insulation, or foundation issues that impact final costs.

Timeline and Professional Requirements

The complete process typically takes 4-6 months including permit approval (6-10 weeks in Ottawa), with construction spanning 8-12 weeks. All electrical work requires ESA permits and licensed electricians, while gas connections need TSSA-certified technicians. Attempting unpermitted work creates serious liability issues and can affect your home insurance and resale value.

For dedicated basement expertise and secondary suite conversions, visit our specialists at Ottawa Basements (https://ottawabasements.com). Want to discuss your specific property and get an accurate estimate? Contact Justyn Rook Contracting for a free consultation - we'll assess your space, explain the permit process, and provide a detailed quote based on your goals and budget.