Additional Dwelling Unit (ADU) and Multiplex Conversions are integral parts of Gentle Density strategies, which aim to increase housing availability without drastically altering neighborhood character.
These housing options fall within a broader spectrum called the Missing Middle, which includes various low- to mid-density housing forms, filling the gap between single-family homes and high-rise apartments.
Financing an additional dwelling unit or a multiplex conversion in Canada can be done through several options, depending on your financial situation, the property's equity, the project's scope and intended use.
An Additional Dwelling Unit (ADU)—also called an Accessory Dwelling Unit or Auxiliary Dwelling Unit—is a separate living space with its own entrance, kitchen, and bathroom, making them independent from the main home but still located on the same property. ADUs can be attached to the primary home (e.g. secondary suites) or detached (e.g. garden suites).
Learn more about ADUs >
Secondary Suite
Also known as Rear-yard Suites, Backyard Suite or Detached ADU - is a standalone, detached housing unit located in the backyard of a single-family property.
Ideal for housing elderly parents, adult children, or tenants while maintaining privacy.
Laneway House
Also known as Rear-yard Suites - is a detached housing unit built along a laneway at the rear of a property, particularly common in urban areas with laneway access.
Ideal for separate residence for family members or generating rental income.
Garage Suite
Also known as Carriage House or Garage Conversion): A housing unit built above, adjacent to, or within a garage structure.
Ideal for utilizing underused garage space for additional housing.
Garden Suite
Also known as Rear-yard Suites, Backyard Suite or Detached ADU - is a standalone, detached housing unit located in the backyard of a single-family property.
Ideal for housing elderly parents, adult children, or tenants while maintaining privacy.
Multiplex Housing is a Multi-unit residential building with two to four separate housing units, such as duplexes, triplexes, or fourplexes, within a single structure. Each unit functions as an independent residence with its own kitchen, bathroom, and living space. The conversion of the principal dwelling into these multiple units, typically ranging from three to five units is called Multiplex Conversion.
Unlike ADUs—which are secondary units built on the same lot as a primary home—a multiplex is a single building made up entirely of independent housing units.
Duplex, Triplex and Fourplex
Detached home containing two, three, four or more residential units, each of them having an entry from the street. The units can be side-by-side or stacked. This housing type generally has an entry for the ground floor unit, and a shared entry for the units above.
Before starting your ADU or multiplex project, it’s important to be clear about why you are building it. Your motivations will shape key decisions—from how much you invest and the design choices you prioritize to the financing strategy and long-term management plan. Some homeowners build to create rental income, others to accommodate family members, and some to increase their property’s value over time.
Taking the time to define your goals early on will help you stay on track, manage costs effectively, and ensure the final outcome meets your needs. Below are the key personal and financial questions to consider before moving forward.
Disclaimer
Highline Beta does not endorse, validate, or take responsibility for the accuracy, interpretations, conclusions, or opinions expressed in the featured materials and other content. Users should conduct their own due diligence and seek professional advice where necessary. While Highline Beta strives to ensure accuracy and keep content up to date, financing programs, grants, and regulations may change. We encourage users to consult with qualified financial advisors, lenders, or legal professionals before making any financial decisions.
