Lock-off units vs. secondary suites

Lock-off units and secondary suites provide ways to accommodate more households within existing homes. But the two options differ in several important ways.

A secondary suite is a smaller dwelling unit created within your house. It must have its own external entrance and be at least 400 sq. ft. In most homes, the basement is the natural location for a secondary suite. Secondary suites are allowed in single-family homes and duplexes. Each side of a duplex can have its own secondary suite, allowing up to four dwelling units in one duplex.

Lock-off units, by contrast, are permitted only in duplexes, not single-family homes. They must have an external entrance and an internal door connecting them to the main dwelling unit. The idea is that the unit can be “locked off” periodically to create a separate dwelling for rental, then opened to become part of the main home when it is not in use. Lock-off units must be between 280 and 320 sq. ft.

So, which option should you choose?

The answer depends on what is permitted in your home and what you value most. Each half of a duplex can contain either a lock-off unit or a secondary suite, but not both. A single-family home can contain a secondary suite, but not a lock-off unit. Because of their size restrictions, lock-off units would generally need to be studios, while secondary suites can potentially include a bedroom. If you want rental income from a long-term rental and do not mind giving up some of your home’s space, a secondary suite may be the better option. If you want more flexibility, a lock-off unit may suit you better.