Why legal matters
A legal secondary suite has been permitted, inspected and built to Alberta's safety codes. It protects the people living in it, keeps your insurance and resale on solid ground, and lets the suite be listed on the City of Calgary's Secondary Suite Registry, the public list of suites that have been registered and inspected.
An unpermitted suite can be difficult to insure, harder to sell, and expensive to bring up to code later, because walls and ceilings may have to be opened for inspection.
Check your property first
Start with the City's online address lookup. In most low-density districts a secondary suite is a permitted use, which means no discretionary planning review if the design meets the Land Use Bylaw and the building, fire and safety codes. If a suite is discretionary on your property, or your design doesn't meet the bylaw as written, you also need a development permit.
Since the City's rezoning repeal took effect on August 4, 2026, a property can have either a secondary suite or a backyard suite, not both. If you are weighing the two, decide before you design.
The permits you will need
- A building permit, for structural and life-safety compliance.
- An electrical permit, applied for separately.
- Plumbing, gas and mechanical permits for the trades work involved.
- A development permit, only if suites are discretionary for your address or the design doesn't meet the Land Use Bylaw.
- For homes built before 1990, an asbestos abatement form, submitted before the permit is released.
The safety requirements that shape the design
- Fire separation between the suite and the main home: solid-core wood doors at least 45 mm thick with self-closing devices, and at least 12.7 mm drywall on both sides of separating walls, with taped joints.
- Interconnected smoke alarms, so an alarm in the suite also sounds in the main home and the reverse, installed in each bedroom, common space and mechanical room.
- An egress window in every bedroom that opens fully, with at least 0.35 m² of unobstructed opening.
- A ceiling height of at least 1.95 m in a basement suite, which may drop to 1.85 m under ducts and beams.
- Backflow protection designed for two dwelling units. The City has reminded builders that a normally open backwater valve may serve only one dwelling unit, and a secondary suite counts as a separate unit.
Deadlines and fees in 2026
Through the Secondary Suites Amnesty Program, the City has waived suite registry fees until December 31, 2026. If you have an existing suite that was never permitted, or you are planning a new one, this year is the cheapest time to get it on the registry.
What a legal suite costs
In Kay2's 2026 cost guide, a legal secondary suite with a separate entry, full kitchen and bathroom, fire separation and permits typically runs $90,000 to $140,000. Older homes can add cost for electrical service, egress window wells or drainage, so an early site visit is worth it.
Kay2 plans, permits and builds basement developments across Calgary, including the drawings the City needs. Book a consultation and we can check your property and walk you through the options.
Sources
- City of Calgary: Add a new secondary suite
- City of Calgary: Repeal of citywide rezoning
- City of Calgary Building Services advisory: Secondary suites, backwater valves and protection from backflow (Oct 2022)
- Kay2 Contracting: The Calgary Renovation Cost Guide 2026
Checked October 5, 2026. Programs and rules change; confirm current details with the source before you rely on them.
Talk it through with Kay2
Every project starts with a complimentary consultation with one of our estimators.
