Minimum basement ceiling height in Alberta: suites and rooms

In Alberta, a basement suite needs ceilings at least 1.95 m (6 ft 5 in) high, and at least 1.85 m (6 ft 1 in) under beams and ducts (NBC(AE) 2023, 9.5.3.1). A basement without a suite follows the code's room table instead: 2.1 m (6 ft 11 in) over part of each finished room, and 2.0 m (6 ft 7 in) of clear height where people walk in unfinished space. Both come from the National Building Code, 2023 Alberta Edition, whose second printing has been in force since 17 August 2026.

What ceiling height does a basement suite need in Alberta?

At least 1.95 m (6 ft 5 in). The code's wording is short: "Ceiling heights in secondary suites shall be not less than 1.95 m." Under beams and ducting, the clear height can drop to 1.85 m (6 ft 1 in) (NBC(AE) 2023, 9.5.3.1). The rule covers every secondary suite, in a basement or not.

Three details catch people out.

Measure finished to finished. Room heights are measured "between finished floor and ceiling surfaces" (NBC(AE) 2023, 9.5.1.1). Flooring, underlay and drywall all come off the height you measure today from the slab to the joists.

The 1.85 m is for beams and ducts only. It doesn't lower the ceiling for the whole suite. The City of Calgary says heights "can be reduced to 1.85 m where ductwork and beams make drop ceilings necessary" (The City of Calgary, 2026).

Full height has to reach the door. The part of a room that meets the minimum must be "contiguous with the entry or entries" (NBC(AE) 2023, 9.5.3.1). You can't reach the full-height part of a room only by ducking under a bulkhead.

Doors follow the ceiling down. In a suite built to the 1.95 m ceiling rule, doorways can be sized for doors 1 890 mm (6 ft 2 in) high instead of the usual 1 980 mm (6 ft 6 in) (NBC(AE) 2023, 9.5.5.1).

Side by side in millimetres, the basement numbers are 1 950 mm for a suite ceiling, 1 850 mm under its beams, 2 100 mm over part of a room outside a suite, and 2 000 mm of clear height in unfinished space.

What does "over the lesser of" mean in Table 9.5.3.1?

It means the 2.1 m (6 ft 11 in) ceiling only has to cover part of a room: the whole room or the area in the table, whichever is smaller. A secondary bedroom larger than 3.5 m² (38 sq ft) needs 2.1 m over 3.5 m² of its floor, and the rest of its ceiling can be lower. A bedroom smaller than that needs 2.1 m over all of it. The area is measured at floor level (NBC(AE) 2023, Table 9.5.3.1).

For a sense of scale, 3.5 m² is a square about 1 871 mm (6 ft 2 in) on a side. The table applies to homes, including basements developed without a suite. Inside a secondary suite, the 1.95 m rule replaces it.

Here's the table as printed in the second printing, as of September 2026:

Note: these are code minimums, not recommended heights; inside a secondary suite, 1.95 m and 1.85 m apply instead.

The code's "master bedroom" is the main or primary bedroom. For ceilings, the only difference from other bedrooms is the larger area: 4.9 m² against 3.5 m². The bedroom size guide covers the rest of what a bedroom needs.

How much headroom does an unfinished basement need?

2.0 m (6 ft 7 in) of clear height, under beams and "in any location that would normally be used for passage" (NBC(AE) 2023, Table 9.5.3.1). In practice, that's the path to the furnace, the laundry and the storage shelves.

The row sets a clear height only, with no ceiling height, so away from walking routes the code is silent. It matters when you finish part of a basement and leave the rest: the finished rooms follow the table or the suite rules, and the unfinished part follows this row.

How much headroom do basement stairs need?

1 950 mm (6 ft 5 in) for stairs serving a house or a house with a secondary suite, and 1 850 mm (6 ft 1 in) where stairs sit under beams and ducting in a suite. Other stairs need 2 050 mm (6 ft 9 in) (NBC(AE) 2023, 9.8.2.2).

Headroom is measured straight up from a line joining the nosings (the front edges of the treads and landings) to the lowest point above, across the stair's clear width. A duct or a beam crossing the stair counts. The stairs guide has the rise, run and handrail numbers.

What does the City of Calgary ask for in a basement suite?

Every suite needs a building permit, and the City's page for new suites spells out the height rules in plain terms. These are the items on it that involve height or clearance, as of September 2026 (The City of Calgary, 2026):

Note: this is the City's plain-language summary; the code text governs, and the City's plans examiners and inspectors decide.

The same page asks for an egress window in every bedroom, covered in the egress window guide. For permits, costs and the layout mistakes that cost the most, see the legal basement suite guide.

What if your basement ceiling is too low?

Measure first. If the finished height comes out short, OAF Construction, a Calgary builder, says structural work such as underpinning or benching "may be considered" (OAF Construction, 2026). Its 2026 planning ranges:

• A bench footing, which lowers part of the floor: $3,000 to $8,000.
• Full underpinning: $15,000 to $35,000.

OAF adds that the method depends on your plans, foundation and site, and advises measuring and confirming before you treat underpinning as a budget line. Neither range is a quote.

Ducts and beams are the other lever. The 1.85 m allowance applies only under them, so their route decides where the low ceilings land. Running ducts over a hallway or a bathroom keeps the bulkheads out of the living room and bedrooms.

The Calgary communities with the most basement development permits since 2023, from the City's permit data:

Among the 97 communities with a page on this site. Declared value is what the applicant wrote on the permit application. It is not a quote and runs below real costs. Medians are shown only where a category has at least 5 permits. Source: City of Calgary open data (building permits, development permits, secondary suite registry, census 2021 population, census 2021 households, civic census 2019, land use districts), retrieved 5 October 2026.

Where a full-size walkthrough fits

A floor shows the plan, not the ceiling, so the useful part here is where the low spots land. At 1to1 Plans Calgary, your plan is lit at full size from inside a walkable LED floor, room by room, with room names and dimension lines. Mark bulkheads and beams on the plan, and you can walk the bedroom, the stair and the route to the laundry and see what sits under them. Elevations go up on a wall-size screen behind the floor.

You can move freestanding walls, sofas and a dining table into place, make changes on the spot and keep the recording of the session. Sessions are quoted for the plan by its size, the quote is free, and there's nothing to pay at booking (get a quote). Send your plan as a PDF or DWG at least three days ahead. See renovations and suites, the other room size guides, or book a session.