2024 OBC UPDATE Dead End Corridor Within a Restaurant

Date of Publication:  June 18, 2024   [2022.01.V-02.C]

Subject: Dead End Corridor Within a Restaurant 2024 OBC UPDATE  

Summary of updates: Numbering of sentences within Article 3.3.1.9.

2024 Ontario Building Code [O.Reg 163/24 Amended to 5/25] Reference(s):

3.1.2.6.(1) Of Div.B.

3.3.1.9.(5) Of Div.B. 

3.3.1.9.(6) Of Div.B.

3.3.2.5. Of Div.B.

3.7.6.3.(1) Of Div.B. 

2020 National Building Code of Canada Reference(s):

3.3.1.9.(7) Of Div.B.

 Incoming Request:

Restaurant designs often provide access to the washrooms via a dead end hallway. Given the small occupant load of the washrooms, the short amount of time spent there, and the fact that the entire restaurant is located within an individual suite, would the hallway be considered a corridor for the purposes of 3.3.1.9.(6).?

Would there be an allowance for a restaurant less than 30 or a hallway of limited length? 

See Sketch 1 below:

Executive Summary:

Dead end corridors or hallways in suites of assembly occupancy may meet the intent of sentence 3.3.1.9.(6) based on the interpretation of the word corridor or the physical layout of the suite.

Discussion & Considerations:

Sentence 3.7.6.3.(1):

Sentence 3.7.6.3.(1) requires rooms containing water closets to be located in such a way as to not open directly onto dining or food preparation areas. This results in designers creating alcoves, hallways or corridors to separate the two areas.

Definition of corridor:

 “Corridor” is typically defined in the dictionary as “a long narrow passage in a building, with doors that open into rooms[i]” or “a passageway (as in a hotel or office building) into which compartments or rooms open[ii]”. Both sources also list “hallway” as a synonym. This is different from how the word “corridor” is treated in the OBC.  The OBC defines public corridor as “a corridor that provides access to exit for more than one suite”.

The OBC also uses the term “corridor used by the public”, which is undefined. Article 3.3.2.5. regulates corridors used by the public in assembly occupancies. By looking into the context in which that term is used in this article, and the related requirements for fire separations, it is clear that the space referred to in this question is not a corridor used by the public. 

Dead end corridor in a restaurant 30 patrons or less:

If a restaurant has an occupant load of 30 or fewer persons, OBC sentence 3.1.2.6.(1) permits the occupancy to be classified as an E occupancy, and 3.3.1.9.(10) would apply. This sentence permits a 9m dead end corridor as long as the doors opening onto the corridor have self-closing devices.

Dead end corridor in a restaurant more than 30 patrons:

If the restaurant has an occupant load greater than 30, sentence 3.3.1.9.(6) will apply to a corridor.  As the OBC is objective based, we must first look at the objectives and functional statements of this sentence[iii]. According to SA-1, this sentence regulates dead end corridors in an effort to facilitate timely movement of persons to a safe place and avoid delay in evacuation of a building.

For more clarity we can look to the similar provision in the National Building Code of Canada[iv] (NBC). Sentence 3.3.1.9.(7) of Div. B of the NBC also limits the length of dead end corridors, and the intent statement refers to occupants travelling into a dead-end corridor and 

not being able to retrace their steps due to a crush of people or untenable conditions, and that a corridor located entirely within a suite is likely to be familiar to the occupants, also reducing the risk.[v] Given this more specific information, the proposed scenario appears to meet the objective of 3.3.1.9.(6), specifically, the likelihood of a person who is exiting under emergency conditions, travelling down a short corridor that plainly does not lead to an exit, and then being trapped there by others doing the same appears very remote.

Conclusion:

Taking into account the intent statements of the NBC, and looking at the context and use of the word corridor in the OBC, it is reasonable to conclude that the proposed scenario meets the intent of sentence 3.3.1.9.(6), either by the interpretation that the hallway in question is not a corridor, or that the risk to occupants posed by this short dead-end corridor is very low. 

Final Recommendation(s):

When evaluating a proposed design, a building official may want to consider hallways that are neither public corridors nor corridors used by the public as not being “corridors” for the purposes of 3.3.1.9.(6). 

Alternatively, if a building official considers all narrow passageways in a floor area to be “corridors”, they may want to consider if a corridor of a limited length, located entirely within a suite, would be deemed to be in compliance with 3.3.1.9.(6). 

Intent 1:

To limit the probability that persons will enter a dead end portion of a corridor during an emergency situation and be prevented from retracing their steps as a result of crowd pressure or untenable conditions, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.

Intent 2:

To exempt a corridor entirely within a suite from the requirement in the remainder of the Sentence which restricts the length of dead end portions on the basis that the occupants are familiar with the suite arrangement and are expected to make appropriate decisions in an emergency.

In evaluating these designs, the following points are key: 

Occupant load of the suite:

  Length of the corridor:

Overall layout:

Additional Signage:

Subsection 3.4.2. :

Referenced Documents:

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.