Secondary Dwelling Units / Basement Apartment Plans in Ottawa

At R. Viau Drafting & Design, we specialize in designing Secondary Dwelling Units (SDUs) that add value, flexibility, and functionality to your property. Whether you're looking to create a legal basement apartment, garden suite, or coach house, we provide expert guidance and tailored design solutions to meet local zoning and building code requirements in Ottawa and surrounding areas.

With over 35 years of experience, our team ensures that every SDU project is thoughtfully planned, efficiently executed, and seamlessly integrated into your existing property.

What is a Secondary Dwelling Unit?

In Ottawa, homeowners now have the flexibility to add up to three residential units on a single property, thanks to recent legislative changes under Bill 23. Previously, zoning rules allowed for only two.

These additional living spaces (often referred to as accessory or secondary units) are fully independent dwellings that can either be built as standalone structures like backyard suites or laneway homes, or created by repurposing existing areas such as basements, garages, or attics. Typically smaller than the main residence, they offer practical solutions for expanding housing availability in urban neighborhoods.

Key Characteristics

Independent Living: Secondary units are fully equipped with essential amenities such as a private kitchen, bathroom, and living area - allowing for complete day-to-day functionality.

On-Site Placement: These dwellings are situated on the same parcel of land as the main home and can be either integrated into the primary structure or built as a separate building.

Versatile Functionality: Common uses include generating rental income, housing extended family, providing space for remote work, or serving as private guest accommodations.

Advantages of Secondary Units

Additional income

Leasing an additional living space can generate consistent passive earnings.

Space for family

These spaces offer comfortable accommodations for elderly parents, grown children, or other family members, supporting multi-generational households.

Increased property value

Incorporating an ADU or SDU can increase your property’s worth by providing additional living areas.

Affordable housing

Contribute to easing housing shortages by expanding the rental options within a community.

Our Drafting Services

Site Evaluation & Feasibility Study

Analyze the lot size, setbacks, and access points
Check compliance with zoning bylaws, OBC, and fire code.
Identify best location for SDU (basement, garage, addition, or detached structure)

Detailed Drafting Plans

Produce complete, permit-ready construction drawings including:
Floor plans
Elevations and sections
Site and grading plans (if applicable)
Fire separation and egress requirements
HVAC, plumbing, and electrical layout coordination

Permit Application Support

Prepare and organize all documentation for municipal permit submission
Submit plans and respond to comments or revision requests from city officials
Coordinate with other professionals (engineers, surveyors) if needed for approval