Do Protection Requirements Apply to Front Wall Openings Near Side Boundaries in Commercial Buildings?

Acknowledgment

While this may be obvious to some, others have likely raised the same question. This article is intended for those who are interested in exploring or confirming their existing knowledge. It offers my professional opinion, while inviting others to share their perspectives and interpretations of this clause.

The short answer is NO—protection is NOT required for front wall openings in commercial buildings located near side boundaries, [In my humble opinion] based on my reading of Clause C4D3 of the BCA Volume 1 and the accompanying Guide to the BCA.

Let's consider an example of an industrial building built to a side boundary, with its associated front external wall openings positioned less than 3m from the side boundary (fire source feature) but facing the front road. The openings in question are located more than 6m from the far boundary of the road, and in this scenario, they don’t need to be protected. This conclusion aligns with many examples we see in practice, such as shopfronts facing public roads, which are typically not protected.

https://ncc.abcb.gov.au/editions/ncc-2022/adopted/volume-one/c-fire-resistance/part-c4-protection-openings

Key BCA Requirements for Openings Near Boundaries

Clause C4D3 of the BCA states that protection of openings is only necessary if the distance between the opening and the fire-source feature it is exposed to is less than:

• 6m from the far boundary of a road, river, or similar feature.

As such, for external wall openings that are less than 3m from a side boundary, but which face a front road and are more than 6m from the far boundary of the road, protection is not required. These openings are not considered exposed to the side boundary but to the far boundary of the road, and since they exceed the 6m distance, they fall outside the requirement for protection.

Additional Insights from Specification 5 Fire-resisting construction of the BCA Guide

https://ncc.abcb.gov.au/editions/ncc-2022/adopted/volume-one/c-fire-resistance/5-fire-resisting-construction

The Guide to the BCA further illustrates situations where building elements are not considered exposed to fire-source features. These include:

• Levels that are completely located underground with embankments retaining the earth to the boundary line.
• Floors located more than 15m above the exposed storey level.

It also mentions specific conditions under which openings need protection:

• Openings within 3m of a side or rear boundary must be protected (C4D3(2)(a)).
• Openings within 6m of the far boundary of an adjoining road, river, or similar feature must be protected if located in a storey above ground level (C4D3(2)(b)).

One critical point in the guide is the need for a case-by-case assessment to determine what constitutes a “reasonable distance” from ground level for protection of openings under C4D3(2)(b). This introduces an element of subjectivity into the interpretation, which may require discussions with the relevant authority to reach a decision.

Defining “Reasonable Distance” from Ground Level

The notion of a "reasonable distance" often invites professional judgment, which can be complex depending on the specific building configuration and local context. In my experience, this decision usually hinges on factors like the overall height of the building, proximity to surrounding structures, and potential fire hazards. Engaging with the fire authority or building certifier early in the design process is critical to avoid disagreements later on.

Varying Approaches by Certifiers

Some certifiers take slightly different approaches. They differentiate based on whether the front walls are built right up to the front boundary or not. If the walls are built directly on the front boundary with no setback, they typically don’t require protection for front windows that are less than 3 meters from the side boundary, as long as the windows face the road and the fire source feature on the opposite side of the road is at least 6 meters away. Simply because there isn’t enough space to add a nib wall.

However, if the front wall is set back some "distance" from the boundary (a distance that is undefined and open to interpretation!), they may request a nib wall to project a certain "distance" (again, undefined how long?) to provide shielding and protection for those openings.

Do you agree with this approach? Why? or Why not?

Conclusion and Open Questions

To sum up, protection of front wall openings near side boundaries (for 2-9 buildings), particularly in cases like industrial & commercial buildings or shopfronts facing public roads, is typically not required if they meet the criteria outlined in Clause C4D3. However, the question of what constitutes a "reasonable distance" from ground level remains a critical element that often requires professional judgment and collaboration with regulatory authorities.

Have you encountered similar challenges in your projects, particularly with interpreting “reasonable distance” requirements? I'd be interested to hear how others have approached these decisions, especially in unique or contentious cases. Let's continue the conversation.

Further Clarification based on enquires that I have received: FRL vs. Protection of Openings

A common point of confusion relates to the distinction between Fire Resistance Levels (FRL) and the protection of openings in external walls. It’s important to clarify that these two requirements serve different purposes and are governed by different aspects of the BCA.

While Specification C1.1 (Spec 5) states that a building element is exposed to a fire-source feature if any horizontal line between the element and the fire-source feature is unobstructed by a fire-rated wall, this primarily addresses the overall fire resistance of building elements rather than the specific requirements for protecting openings in front facades.

The focus of my article was on the protection of openings in external walls facing public roads, not on the FRL of external walls. However, it's worth noting that walls built within 3 meters of a side or rear boundary, or within 6 meters of another building of a different classification on the same lot, must comply with the FRL requirements outlined in Specification C1.1. The required FRL will depend on the distance from the boundary (<3m, <1.5m, etc.) and the type of construction used.

To summarize:

• Openings in side or rear walls within close proximity to boundaries must comply with both protection requirements for openings and FRL compliance.
• Openings in front walls (even within 3 meters of a side boundary) typically do not require protection, provided they meet the conditions discussed earlier in the article. However, the FRL requirements for the walls themselves must still be adhered to, regardless of the orientation of the wall.

Disclaimer:

This article is intended for general informational purposes only and should not be taken out of context. It does not pertain to any specific site or situation. We strongly recommend that you seek independent planning, fire safety, or legal advice tailored to your particular circumstances. Do not rely solely on the opinions or information provided in this article or any associated comments.

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Regards

Firas Naji

13 September 2024