Glass balustrades in Canadian buildings must meet both structural glazing requirements and guard height and opening requirements under the National Building Code of Canada 2020 (NBC 2020), with the specific rules depending on occupancy type and location.
Guard Height
Guards, including glass balustrades, must be provided where required by Section 9.8.8 of the NBC 2020. The intent of those provisions is to limit the probability that guards will not be high enough to provide reasonable fall protection, which could lead to persons falling [Source: NBCC 2020 Supplement - Intent Statements, Page 1293, Section 9.8.8.3.(1)]. The index confirms that guard requirements, guard heights, and glass-in-guards provisions are governed by Articles 9.8.8.1 through 9.8.8.7 [Source: National Building Code of Canada 2020, Page 777].
Glass Type in Guards
The NBC 2020 index confirms that glass in guards must conform to Article 9.8.8.7, and that the applicable glass standards are referenced under Section 9.6.1 [Source: National Building Code of Canada 2020, Page 777]. Glass used in guards is therefore subject to the safety glazing standards cited under Section 9.6, which require either:
Safety glazing of the tempered or laminated type conforming to CAN/CGSB-12.1, "Safety Glazing," or
Wired glass conforming to CAN/CGSB-12.11-M, "Wired Safety Glass" [Source: National Building Code of Canada 2020, Page 836, Section 9.6.1.4.(1)]
Structural Design of Glass
The structural design of glass panels must satisfy the area and thickness requirements of Article 9.6.1.3, which sets maximum glass areas based on wind pressure zone and terrain. For example, in an open terrain zone where the 1-in-50 hourly wind pressure is less than 0.55 kPa (11.5 psf), a 6 mm (1/4") tempered pane may not exceed 3.59 m2 (38.6 ft2) [Source: National Building Code of Canada 2020, Page 836]. The intent behind these structural provisions is to limit the probability that glazing will fall significantly below expected performance under impact or wind loads, which could lead to breakage and harm to persons [Source: NBCC 2020 Supplement - Intent Statements, Page 1239, Section 9.6.1.3.(1)].
Opening Restrictions
Guards must also limit openings so that small children cannot fall through or become trapped. The NBC 2020 restricts openings in guards to prevent passage of a 100 mm (4") sphere in most occupancies, and guard elements must also satisfy deflection limits under load. The intent is to prevent children from pushing their head or body through a guard and becoming trapped [Source: NBCC 2020 Supplement - Intent Statements, Page 1293, Section 9.8.8.5.(1)].
Important Note on Passages Provided
The passages provided do not reproduce the full text of Articles 9.8.8.1 through 9.8.8.7 directly. The specific minimum guard heights (generally 900 mm (35 7/16") in residential interior locations and 1 070 mm (42 1/8") in most other locations) and the maximum openings for glass balustrades are referenced in those articles, but their full regulatory text was not included in the passages available for this answer. Designers should consult Part 9, Section 9.8.8 of the NBC 2020 in full, and also confirm whether a provincial code such as the Ontario Building Code or BC Building Code introduces any amendments to these requirements for their jurisdiction.
Sources cited
NBC-INTENT • 2020 • p. 1293 • §Section 9.8.8.3.(1)
NBC • 2020 • p. 777
NBC • 2020 • p. 836 • §Section 9.6.1.4.(1)
NBC • 2020 • p. 836
NBC-INTENT • 2020 • p. 1239 • §Section 9.6.1.3.(1)
NBC-INTENT • 2020 • p. 1293 • §Section 9.8.8.5.(1)
This answer is AI-generated from the cited sources. While CodesWise grounds every response in the official code documents, you remain responsible for verifying the requirements that apply to your specific project. Always confirm against the authoritative code for your jurisdiction.