Adding a secondary suite

The Alberta Building Code requires a minimum floor to ceiling height of 1.95 m for basement suites.

• Ceiling heights can be reduced to 1.85 m where ductwork and beams make drop ceilings necessary.
• Doors within the suite may be reduced to 1.89 m where required. 

Horizontal sliding window

Vertical sliding window

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The main residence and suite must have at least one exit that leads directly outside. This may be a door that leads to an exterior stair or a door to a common set of interior stairs that is separated from both the main residence and suite.

• A stairway used in an exit requires a minimum width of 860 mm and must have at least one handrail.
• Handrails should be mounted between 800 mm and 965 mm above the stair. The height is measured vertically from the front edge of the stair tread.
• At least one light fixture that can be switched both on and off at the top and bottom of the stairs is required.
• A landing must be provided at the top and bottom of all stairs. The landing must be at least 860 mm long and at least as wide as the stairs.
• Doors serving the exit are required to be a minimum of 810 mm wide and 1.89 m high. Utility rooms, laundry rooms, furnace rooms and all other doors leading to the exit must also be at least 810 mm wide. 

• The window must have an unobstructed opening of 0.35 m² in area and a minimum height and width of 380 mm. See the acceptable window style illustration below for examples and additional requirements.
• When a window well is required, a clearance of 760 mm must be provided in front of the window. If a casement-type window is used, it must swing open a full 90 degrees. See the window well illustration below for more details.
• Security bars serving a bedroom window must be removable from the inside without the use of tools, keys or special knowledge. A large majority of security bars do not meet the requirements and are not accepted. 

There are additional requirements to consider when the only exit for a suite is served by an exterior staircase.

When an unenclosed exterior exit stair or ramp provides the only exit from the secondary suite and could be exposed to fire from windows in the primary dwelling, those windows that are less than 3 m horizontally and less than 10 m below or less than 5 m above the exit stair need to be protected. This may be achieved by installing glass block or wired glass in fixed steel frames. It is important to know that only fixed, non-operable windows can be protected in this way. Bedroom windows must be operable.

Alternately, the construction of a roof over the entirety of the exterior exit stair may be provided. The roof must be constructed of solid construction material such as wood, metal or concrete. Option B shows an exterior stairwell with a roof providing protection from the window above it.​

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Option A: uncovered entry​

The Alberta Building Code requires all foundation footings in Calgary to have at least 1.2 m of ground cover for protection.

• New exterior exit stairs must include a shallow foundation design by a registered professional engineer, since stairwell excavation impacts the required frost cover.
• Retaining walls required alongside the new staircase opening often retain greater than 1 m of soil. In these cases the retaining wall may be required to be included in the engineered design. 

Secondary suites must have:

• A supply of hot water and at least one kitchen sink, bathroom sink, toilet and a bathtub or shower.
• A back-flow prevention device on the branch drain of the sanitary sewer line. 

A common electrical panel can serve both suites, provided there are no shared branch circuits between the suites. It is recommended the electrical panel be located in a common area, or that each tenant has access to the electrical panel. 

Use the secondary suite electrical load calculation sheet to ensure your current electrical service is adequate. Before an electrical permit rough-in inspection occurs, the form should be emailed to us. If the main electrical service must be increased from 60 amps, 100 amps, or 200 - amp service, please have your Contractor contact ENMAX.

Installing a furnace or gas appliance in secondary suites

An independent heating and ventilation system that includes independent ductwork is required for secondary suites.

Several heating systems can be used:

• A second forced air furnace may be installed for the suite.
• Electric baseboard heaters or hydronic radiant heating may be installed with an independent ventilation system, like a heat recovery ventilator.

If a single boiler is being used for both units, separate zone controls are required for each unit. Heating equipment must include easy access to compartments for inspection, maintenance and cleaning.

An independent heating and ventilation system that includes independent ductwork is required for secondary suites.

Several heating systems can be used:

• A second forced air furnace may be installed for the suite.
• Electric baseboard heaters or hydronic radiant heating may be installed with an independent ventilation system, like a heat recovery ventilator.

If a single boiler is being used for both units, separate zone controls are required for each unit. Heating equipment must include easy access to compartments for inspection, maintenance and cleaning.

On a property located inside the airport vicinity protection area (AVPA), the suite must be located in the basement of an existing single family development.

Chat with us, or contact the Planning Services Centre at 403-268-5311 for more information about secondary suites in the AVPA.