A building permit is required to build a secondary suite into your home.
Secondary suites are self-contained units inside what would normally be considered a single-family home. Homeowners often rent these suites out to tenants.
Dwellings with secondary suites need at least one exit that leads directly outside. The two units can use a common entrance/exit area if the area is separated from the units by a smoke-tight barrier.
Entrance/exits must be clearly marked with a label affixed to the doors.
Each bedroom needs at least one window that meets code requirements as a second means of exiting the bedroom. This means a window with an unobstructed opening at least 3.77 square feet, with no dimension less than 15 inches.
Common walls must use 1/2” drywall, and be separated by a smoke-tight barrier and sound control.
The sound control needs to meet a sound transmission classification rating of at least 43. This can be achieved through sound-resilient channels and bat insulation, or a specialized wall-ceiling assembly.
A smoke-tight barrier includes drywall that is taped, sanded, and sealed at all junctions and penetrations, and floors must also include a floor covering. Doors must be at least 1 3/4” thick with a solid core and an approved self-closing device.
The ceiling of a secondary suite must be at least 6’5” feet from the floor.
New smoke and carbon monoxide alarms must be installed in the secondary suite, and be interconnected between the primary and secondary units.