Date of Publication: January 19, 2025 [2023.19.V-02.C]

Subject: Exit Through A Condominium Lobby 2024 OBC UPDATE

Summary of updates: No changes

Incoming Request:

A Part 3 condominium building of 22 storeys is being proposed. Two separate exit stairwells serve the above-grade storeys, with one of the exit stairs emptying into the lobby on the ground floor, as permitted by Article 3.4.4.2. of Division B. Two questions have arisen:

What amenities are permitted in this “exit lobby”, i.e. tenant mailboxes, concierge desk, or a seating/waiting area?

What rooms are permitted to open onto the “exit lobby”, i.e. an elevator machine room, CACF (Central Alarm and Control Facility) room, parcel storage room, mail sorting room, a room containing tenant mailboxes, or a concierge/security office?

Executive Summary:

Where a proposed design includes exiting through a lobby (“exit lobby”), limited types of rooms are permitted to open onto the lobby and the lobby must be designed for no purpose other than exiting. Storage rooms are not permitted to open onto the exit lobby, but CACF and elevator machine rooms may or may not be considered service rooms and should be individually evaluated as to their fire risk and impact on the exit lobby. Where tenant mailboxes, a seating area, or a concierge desk are proposed, they may be permitted in limited circumstances where they can be shown to not be detrimental to the function of the lobby as an exit.

Discussion and Considerations:

Exiting through a lobby is permitted by Article 3.4.4.2., however the exit lobby must comply with the requirement of sentence 2(a) through (g). In particular, clause (e) states that the lobby must meet the requirements of an exit (with 4 exceptions). Article 3.4.4.4. contains the most obvious exit requirements, but Article 3.1.13.2. regulates flame spread rating of interior finishes in exits and Article 3.1.13.7 regulates flame spread rating and smoke developed classification for exits in high buildings.

The crux of this question lies in sentences 3.4.4.4.(6) which states an exit can be designed for “no purpose other than for exiting” and sentence (8) which describes what rooms may open onto an exit,[ subject to the allowance in Clause 3.4.4.2.(2)(e)].

Purpose of an exit lobby: While traditional residential lobbies often contain a seating area, a concierge desk, or tenant mailboxes, having these design features located in an exit lobby could be seen to facilitate a use other than for exiting. In certain limited circumstances, where it can be shown that the location, amount or nature of these additional design features does not impact the safety or function of a lobby as an exit, it seems reasonable to consider allowing them.

Rooms that are permitted to open onto an exit lobby: Sub-sentence 3.4.4.2.(e)(i) prohibits storage rooms and service rooms from opening onto an exit lobby. This would allow a room containing tenant mailboxes (without parcel storage), a mail sorting room, or a concierge/security office to open onto an exit lobby. Furthermore a room containing only a CACF may be permitted based on the idea that it presents a very low fire risk compared to a typical service room. This is supported by Sentence 3.6.2.1.(8) which acknowledges that not all service rooms pose the same risk to the rest of the building. It is worth noting that the OBC Appendix A does not consider an elevator machine room as a service room, and as such, this room should be evaluated as to its fire risk if it is proposed to open onto the exit lobby.

Risk/Benefit Analysis :

Exiting through a lobby poses different risks from a typical uninterrupted exit strategy, since a lobby is a less controlled and defined space than an enclosed exit corridor. To mitigate these risks, the code puts the requirements of 3.4.4.2. in place, in addition to the normal exit requirements of Article 3.4.4.4. As noted above, sentences 3.4.4.4.(6) and 3.4.4.4.(8) are integral to this question. Their functions can be summarized as : protection of egress facilities from hazards, and ensuring egress paths are available and unobstructed for both evacuation, and for emergency services access.

When evaluating a proposed design that includes an exit lobby, the following should be considered:

1. Has a code plan or exiting plan been submitted that clearly indicates access to exits, exits, exit capacities, and travel distances?
2. If the proposed design appears to facilitate uses other than exiting, e.g. seating areas or other architectural features are present that may encourage people to gather in the exit lobby, can this possibility be reduced by separating these spaces from the lobby?
3. If the proposed design includes features such as tenant mailboxes, fire alarm control panel, or seating/waiting area, can it be demonstrated that the objectives of sentences 3.4.4.4.(6) and (8) are not impacted? (See 2. above).
4. Have adjacent spaces (rooms opening onto the exit lobby) been clearly identified and designed in compliance with Articles 3.4.4.2. and 3.4.4.4.?
5. Where an exit lobby appears to be designed to accept furniture (which may or may not be shown on plans), coordination with Fire Prevention officials is highly recommended.
6. Where Canada Post official tenant mailboxes are included in a wall, the fire separation and FRR (where applicable) of that wall will be impacted.
7. Given the possible conflict between the code restrictions of an exit lobby and the desire for building designers to create a welcoming entrance, does the design include a means to make building management aware of the limitations on the exit lobby?
8. The 1995 National Building Code Users Guide also contains commentary that is largely applicable today.

Conclusion :

A lobby that is being used as part of an exit (exit lobby) is not a typical lobby. Designers and end users need to be aware of the limitations on this type of design, and in some cases a means to ensure the space is used as intended may be required. Where a proposed design is not in clear compliance, and the use of the exit lobby or adjacent spaces is not clear, the designer must demonstrate compliance with the functional statements and objectives of 3.4.4.4.(6) and (8).

Referenced Documents:

2024 Ontario Building Code O.Reg 163/24 Amended to 5/25:

OBC Article 1.4.1.2. of Div A, Definitions:

Service room Exit

Flame-Spread Rating

OBC Article 3.6.2.1. Fire Separations Around Service Rooms OBC Articles 3.4.4.2 Exits Through Lobbies

OBC Article 3.4.4.4. Integrity of Exits

OBC Article 3.1.13.2. Flame-Spread Rating OBC Article 3.1.13.7. High Buildings

1995 NBC User’s Guide –

https://nrc-publications.canada.ca/eng/view/object/?id=f4c59aa5-16df-4b40-b9db- d6c65cae71de

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.