Date of Publication: April 24, 2025 [2025.03.V-01.C]
Subject: Guard Requirements for Fixed Windows and Glazing in a Part 9 Building.
2024 Ontario Building Code Reference(s):
Article 4.1.5.14. of Div. B
Article 4.1.5.16. of Div. B
Article 9.8.8.1. of Div. B
Subsection 9.6.1. of Div. B
Incoming Request:
A proposed Part 9 building will have large areas (not adjacent to stairs or ramps) of floor-to-ceiling fixed windows, and/or glazing on both interior partitions and exterior walls.
Can these areas of floor-to-ceiling glass be considered as a wall, or must they be protected by guards as described in Sentence 9.8.8.1.(1)?
Executive Summary:
In Part 9 buildings, glazing or windows need to be protected by a guard or be designed to withstand guard loads only in the locations specified in Sentences 9.8.8.1.(6),(7) and (8).
Discussion & Considerations:
Sentence 9.8.8.1.(1). requires surfaces “to which access is provided” to be “protected by a guard on each side that is not protected by a wall”...” where the fall risk is more than 600 mm. This applies to falls to the exterior of a building or another interior level.
Sentences 9.8.8.1.(4) and (5) speak to protection of openable windows. Sentences 9.8.8.1.(6) and (7) prescribe additional requirements for glazing (or windows) located adjacent to stairs and ramps, and Sentence 9.8.8.1.(8) states that “second floor or higher glazing (or windows) less than 1 m above a floor and in public areas of a residential building must be protected by a guard or meet guard loads”.
The objectives and functional statements for the above sentences relate to reducing likelihood of injury due to slips or falls and facilitating movement of people to a safe place in case of an emergency.
Sentence (1) is the general rule and contains one exception: “except as provided in Sentence (2)”. It does not refer to other Sentences as exceptions. This would indicate that other sentences in the article are additional requirements for specific situations.
Article 9.6.1.4. also speaks to protection of glazing, but generally only requires safety glazing
(which is tested to resist a simulated human impact) in sliding doors, storm doors, large sidelights and in shower enclosures.
Risk/Benefit Analysis:
Protecting occupants from falling from one level to another where there is more than 600 mm of height difference (both interior and exterior), is one of the most obvious objectives of the Building Code. The fact that the Code does not explicitly require walls and windows (in all locations) to meet guard loading requirements may reflect an assumption that typical Part 9 walls with typical Part 9 windows are sufficient to keep occupants from falling through them in normal use (see appendix note A-9.8.8.1.).
New requirements of the 2024 OBC found in 9.8.8.1.(4) and (5) have addressed the risk of children falling from an openable window. Existing Sentences 9.8.8.1.(6) and (7) address the risk that someone could stumble on stairs and fall against or through a window. Existing Sentence (8), addresses the risk that someone could fall through a fixed window in a normal floor area not adjacent to stairs or ramps. However, Sentence (8) is applicable only in public areas of residential buildings. By excluding glazing within dwelling units from the application of Sentence (8), the Code permits fixed glazing to be unprotected by a guard and not meet guard loading, when it is located in general areas of a dwelling unit. This is consistent with other Code requirements that recognize a lesser risk of injury in dwelling units, since people have familiarity with their surroundings.
It should be noted that glazing described in Sentences (6), (7) and (8), must only be “designed to withstand the specified lateral loads for guards as provided in Article 4.1.5.14.” and is not required to be designed as per Article 9.8.8.7 - Glass in Guards, i.e. safety glass per CAN/CGSB-12.1, or wired glass. This idea is reflected in the standard, which identifies doors, sidelights and shower enclosures as most likely areas requiring protection from human impact.
Where an interior glazed panel or partition (or any non-standard wall assembly) is used as a means to separate one floor level from another, Part 9 is silent in terms of lateral loading or protection of glass. However, the wall should provide the same level of protection as that implied by Sentence 9.8.8.1.(1). Since no lateral loads are specified in that Sentence, it may be reasonable to refer to the requirements of Article 4.1.5.14. – Lateral loads on Guards or Article 4.1.5.16. - Walls Acting as Guards. For glazing panels, glass meeting CAN/CGSB-12.1 Safety Glazing must pass a simulated human impact test, and is rated as Class A or B, with Class A resisting the greater impact. Glazed panels and partitions may also be subject to other requirements in Subsection 9.6, and from there must comply with Article 4.3.6.1.
For reference, the Building Officials’ Association of BC has published related interpretations 06-0078r and 24-0011, which found that glazing/windows in exterior walls must meet guard loading where the window is lower than 900 mm above the floor surface.
Final Recommendation:
In a Part 9 building, only glass or glazing in locations described in Sentences (6), (7) and (8) needs to be protected by a guard or designed to withstand guard loads. The Code does not require protection of windows in other floor areas. However it is recognized that s.18(1) of the BCA permits inspectors to request additional documentation, where they have concerns that a wall or portion of it will not satisfy the intent of Sentence 9.8.8.1.(1).
Recommendation to Ministry of Municipal Affairs and Housing:
Provide further commentary on any required protection for fixed windows/glazing within Part 9 buildings in locations other than stairs, ramps and landings.
Referenced Documents:
2024 Ontario Building Code: O.Reg. 163/24 amended to O.Reg. 5/24
- CAN/CGSB-12.1 Safety Glazing
- Building Officials’ Association of BC interpretations: 06-0078r and 24-0011
Disclaimer:
This guidance document is intended to assist building officials by gathering relevant information to interpret the OBC Act and the prescriptive requirements of the Ontario Building Code, and is intended to be a best practice aid for building officials.
The views expressed within this guidance document should not be considered as the official interpretation of legislated requirements based on the Ontario Building Code, as the final responsibility for interpretation rests with the local Authority Having Jurisdiction.
The views of this advisory committee should not be construed as legal advice.