R. VIAU
CONSTRUCTION &
DEVELOPMENTS
Secondary Dwelling Unit Construction in Ottawa
At R. Viau Construction and Developments, we specialize in designing and building custom secondary units that unlock the full potential of your property—while complementing the layout and character of your existing home.
Whether you're adding a legal rental suite, creating a comfortable space for extended family, or planning for future flexibility, we tailor every secondary unit to suit your lifestyle, property layout, and long-term goals. From the initial design to final inspection, our team manages the entire process with a focus on craftsmanship, code compliance, and client satisfaction.
The result is a fully functional, self-contained living space that adds value, versatility, and livability to your home—built to the highest standards and designed for everyday comfort.
What is a secondary unit?
How much does it cost to build a secondary unit?
A secondary unit is a self-contained living space within or on your property that includes its own kitchen, bathroom, and sleeping area. It can be a basement apartment, an attached suite, or a separate structure like a coach house.
Costs depend on size, design, existing conditions, and finishes. On average, expect to invest anywhere from $100,000 to $150,000 or more. We provide a detailed estimate tailored to your project’s scope and goals.
