Coach House Builders in Ottawa

At R. Viau Construction and Developments, we specialize in designing and building custom coach houses that expand your property’s potential while blending seamlessly with your existing home and neighborhood.

Whether you're creating a private guest suite, a rental unit, or a space for extended family, we tailor every coach house to your needs, lifestyle, and lot. With a strong commitment to craftsmanship, quality, and client satisfaction, our team guides you from initial concept through final construction—ensuring your new living space is both beautifully designed and expertly built.

The result is a functional, self-contained unit that enhances your property’s value, flexibility, and long-term livability.

What Is a Coach House?

A coach house is a self-contained secondary dwelling built on the same lot as a main residential home. It can be detached or attached and typically includes a kitchen, bathroom, and sleeping area—making it ideal for multi-generational living, rental income, or guest accommodations.

Why Build a Coach House?

Homeowners across Ontario are turning to coach houses for several reasons:

Generate rental income with a legal secondary unit
Support family members with nearby yet independent living
Increase property value with additional livable square footage
Adapt to changing needs such as a home office or studio space

What can influence the costs

Size and Finishes

The size of your coach house / mini home and it's finishes can greatly impact the overall cost.

Appliances and Materials

The appliances and finishes you choose in your kitchens, bathrooms, floors, etc have a huge impact on the cost of your new units.

Services

Rewiring hydro, new septic systems and new water wells can be costly.

Variance Applications

A variance may be required for your project - these can be complicated and/or costly!

We provide zoning reviews which would identify if your project needs a variance before we start any work.

Typical General Costs

Depending on the many variables and the amount of bedrooms, you can expect a general cost of $150,000 to $500,000.

Our Process - Built Around You

Feasibility Assessment

Our team evaluates your lot to ensure a coach house is possible and compliant with local zoning and building codes.

Zoning and bylaw review
Lot measurements and layout analysis
Access, parking, and service connection checks

Design & Architectural Planning

Our in-house designers work closely with you to create a coach house that’s both functional and aesthetically aligned with your main home.

Custom Floor Plans: Designed around your goals—rental income, family use, or flexible living.
Smart Layouts: Space-saving design features like lofts, built-ins, and open-concept kitchens.