Bathroom building code in Alberta: doors, fans and ceilings

Alberta's building code sets no minimum floor area for a bathroom. What it does set is a doorway for a door at least 610 mm (2 ft) wide and 1 980 mm (6 ft 6 in) high, a 2.1 m (6 ft 11 in) ceiling over the lesser of the room or 2.2 m² (24 sq ft), and an exhaust fan of at least 25 L/s switched in the room (NBC(AE) 2023, Table 9.5.5.1, Table 9.5.3.1 and 9.32.3.7). These come from the second printing of the National Building Code, 2023 Alberta Edition, in force since 17 August 2026 (Government of Alberta, 2026).

Is there a minimum bathroom size in Alberta?

No. In this printing, Section 9.5 holds the method of measurement, combination rooms, barrier-free design, ceiling heights, hallways and doorways, and none of its Articles gives a bathroom a minimum floor area (NBC(AE) 2023, Section 9.5). The code shapes a bathroom through its door, its ceiling, its fan and its glass instead.

Part 9 doesn't set a clearance in front of a toilet or between a vanity and a tub either, so fixture spacing comes down to the fixtures' own instructions and your designer. If someone quotes a "code minimum" bathroom size for Alberta, ask which clause it's from.

The fully accessible bathroom is a separate case. Part 3's universal washroom sizes don't apply to houses, and the barrier-free bathroom guide covers when they do and what they ask for.

How wide does a bathroom door need to be in Alberta?

The doorway must take a door at least 610 mm (2 ft) wide and 1 980 mm (6 ft 6 in) high (NBC(AE) 2023, Table 9.5.5.1). A wider door can be required by the hallway. Where a hallway at least 860 mm (2 ft 10 in) wide serves rooms with a bathtub, shower or water closet, at least one doorway off it must reach one of each fixture type and take a door at least 760 mm (2 ft 6 in) wide (NBC(AE) 2023, 9.5.5.3).

The code's Note explains the intent: some degree of barrier-free access to a home's bathroom. If two bathrooms off the same hall have the same fixtures, only one needs the 760 mm door. If the fixtures are split between two rooms off that hall, both rooms need it (NBC(AE) 2023, Note A-9.5.5.3.). Notes are guidance; the Article is the rule.

The bathroom rules in the code, as of October 2026:

Note: Part 9 minimums for bathrooms in houses, not design sizes. Plumbing work is reviewed separately under a plumbing permit.

How high does a bathroom ceiling need to be?

2.1 m (6 ft 11 in) over the lesser of the bathroom's area or 2.2 m² (24 sq ft). Table 9.5.3.1 lists this row as "Bathroom, water-closet room or laundry area above grade" (NBC(AE) 2023, Table 9.5.3.1). The full-height part must connect to the door: the code says that area "shall be contiguous with the entry" (NBC(AE) 2023, 9.5.3.1). Heights are measured between finished surfaces (NBC(AE) 2023, 9.5.1.1).

That matters under a sloped roof or a duct bulkhead. A bathroom tucked under the stairs or into an attic can have a low ceiling over the tub, as long as 2.2 m² at full height starts at the door. In a secondary suite, the suite's 1.95 m rule applies instead, covered on the basement ceiling height guide.

The drawing shows a common 5 by 8 ft bathroom, 1 524 mm by 2 438 mm, with a 1 524 by 762 mm (60 by 30 in) tub across the end and a 610 mm door. The room is about 3.7 m² (40 sq ft), so 2.2 m² of it, shaded from the door in, needs the 2.1 m ceiling.

What exhaust fan does a bathroom need in Alberta?

At least 25 L/s, about 53 cfm, unless an exhaust intake of the house's principal ventilation fan is in that bathroom (NBC(AE) 2023, 9.32.3.7). The same rule covers a water-closet room on its own, such as a powder room.

The switch has to be a manual switch in the room the fan serves. If the fan also runs on a dehumidistat or another automatic control, the manual switch must still turn it on whatever the setting (NBC(AE) 2023, 9.32.3.7).

The bathroom renovation cost guide covers what moving the fan or the fixtures costs.

Does a bathroom need a window in Alberta?

No. A bathroom can be ventilated in the non-heating season by natural ventilation or by a mechanical system (NBC(AE) 2023, 9.32.2.1). If it relies on a window, the openable area must be at least 0.09 m² (1 sq ft), unobstructed (NBC(AE) 2023, Table 9.32.2.2).

Roughing in a basement bathroom for later? Alberta added a rule here: where roughed-in plumbing is installed for a future bathroom or water-closet room, provision must also be made for its future ventilation (NBC(AE) 2023, 9.32.1.4). In practice that means planning the duct route to the outside while the ceiling is still open.

The ways a bathroom can meet the ventilation rules, as of October 2026:

Note: code minimums for ventilation. A fan larger than 25 L/s is allowed, and the fan's own rating method is set in the code too (NBC(AE) 2023, 9.32.3.10).

What does the code say about shower glass and grab bars?

Shower and tub enclosure glass must meet Class A of CAN/CGSB-12.1, "Safety Glazing" (NBC(AE) 2023, 9.6.1.4). Alberta repeats it in the plumbing facilities section (NBC(AE) 2023, 9.31.2.4). If you're reusing old glass, check it carries that label.

Grab bars are optional in a house. When they are provided, they must resist a load of at least 1.3 kN applied up, down or sideways (NBC(AE) 2023, 9.31.2.3). That means solid backing in the wall. Blocking added during framing lets a bar go in later without opening the finished wall.

Which fixtures must a home have?

Every dwelling unit with a piped water supply needs a kitchen sink, a lavatory, a bathtub or shower, and a water closet (NBC(AE) 2023, 9.31.4.1). Hot and cold water must run to every lavatory, bathtub and shower, and cold water to every water closet (NBC(AE) 2023, 9.31.3.2). A basement suite needs its own full set; the secondary suite fire separation guide covers the walls around it.

In Calgary, new plumbing and any extension or alteration of existing plumbing needs a separate plumbing permit. A building permit comes in when walls move or new openings are cut (The City of Calgary, 2026).

Seeing the bathroom at full size

At 1to1 Plans Calgary, your floor plan is shown at full size on a walkable LED floor, with room names and dimension lines. The studio has a bathtub on wheels, so you can set it in the drawn tub space, stand at the vanity, and check how the 610 mm or 760 mm door swings past the toilet. Changes are made on the spot, and you keep the recording.

Sessions are quoted for the plan, and the quote is free (see pricing). See renovations, the other building code guides, or book a session.