Means of Egress (Part 3 of the NBC)
Means of Egress (Part 3 of the NBC) - Transcript
Slide 1
Hi, my name is Pat Tardif. I'm Technical Advisor at Codes Canada. Today I'm going to talk to you about use and egress.
When there's an incident, the means of egress provide:
- sufficient capacity to get everyone out,
- various routes to alternative protected areas, and
- unobstructed evacuation routes.
Slide 2
This presentation is part of a series of 13 presentations on the 2015 editions of Codes Canada.
Before I begin with the technical content of this presentation, I will speak briefly about the code development system.
It is important to note that the model Codes, which are developed by the Canadian Commission on Building and Fire Codes, must be adopted by provincial/territorial authorities to become law.
This may mean that Code requirements enacted by legislation within your province or territory might differ from what is presented here. Please check with your local authority.
Slide 3
It is also important to point out that the National Codes are not a federal regulation.
This means it is not NRC or Codes Canada that decides what goes into the Codes but you!
Codes Canada facilitates an open, transparent, consensus-based process to come up with improvements.
Over 400 committee members volunteer their time to decide on changes to the next Codes.
All committees are balanced between regulators, industry and public interest so that no single category can outvote the other two.
This process is shown on the slide:
- It typically starts with someone requesting a Code change.
- It continues with technical committees developing proposed changes.
- It involves a public review and the final approval by the Canadian Commission on Building and Fire Codes.
It's a simple process and it depends on your input.
Please go to the Codes Canada website and find out how you can:
- submit code change requests,
- participate in committees, or
- comment on proposed changes during our public reviews.
Slide 4
Before we start, here are some clarifications on the presentations themselves:
- The presentations cover only the changes from 2010/2011 to 2015 Codes and not how to use or interpret the Codes in general.
- The presentations contain only the significant changes - the details are in the handbook. Each presentation contains a reference to the relevant pages in the handbook.
- The presentations stay strictly within the scope of the National Codes and do not cover provincial or territorial variations.
Slide 5
In this presentation, you will learn about changes to:
- exits in nightclubs,
- crossover floors in mid-rise buildings,
- electromagnetic locks in care facilities, and
- landing size in staircases.
The information I will be presenting is found on pages 13 to 16 in your handbook.
Slide 6
This is an image of the ruins following a devastating fire at the Station Nightclub in Rhode Island that killed 100 people in February 2003.
Slides 7-8
Think of a time when you've entered a nightclub.
There was usually one door being guarded by a very large and intimidating bouncer.
His job is to make sure people who get in pay their cover charges and show their ID.
The previous National Building Code (NBC) allowed small entrances to control who got into the club, but this meant the nightclub also had a small exit capacity.
Sadly, after investigating fires like the Station Nightclub, we've concluded that when people need to get out quickly, they go back to the most familiar door - that small main entrance.
With most everyone trying to get out the way they came in, the crowd crush ends up blocking the door leading to many deaths and injuries.
Slides 9-10
Since we can‘t change human nature, we've changed the Code.
The main entrance must now be big enough to let least half of the occupant load get out.
This is only for buildings that:
- are not sprinklered,
- contain an assembly occupancy, Division 2 (dancehalls and bars), and
- have more than 250 occupants.
So now, when patrons need to leave, they'll be able to use the most familiar door to get out safely.
Slides 11-13
Now, let's look at crossover access.
Have you ever been in a staircase where you've felt like you're trapped in a maze?
Let me give you an example. So in keeping with your New Year's resolution, you decide to use the stairs rather than the elevator to get to where you're going.
Once in the stairwell, you find a locked door at the floor you wanted to visit, so you try another floor until you soon realize that all doors are locked, except for the one that takes you outside - and it's January, in Winnipeg, and you don't have your coat!
Now, imagine the same situation and there's a fire near or blocking the exit?
There were gaps in the Code regarding crossover floors, including that they weren't required when there were multiple below grade storeys.
The 2015 NBC now requires crossover floors to be no more than 2 storeys from where you are, regardless if it's above or below ground.
The signage for the crossover floors is improved so that it's easier to find the unlocked doors.
The Code maintains the same restriction of not having multiple storeys without crossover access.
In certain conditions, the Code now allows the use of doors with electromagnetic locks when a crossover access is through a tenant space. This removes the need for a crossover corridor.
Slides 14-17
Interior exit doors on the same floor need to be far enough apart so that they can't be blocked at the same time by a fire.
But, in some building designs, the exterior doors of the stairwells serving the same floor areas are very close to each other.
Any incident (fire, bomb threat, etc.) close by would block both exits, and then you would be trapped.
The 2015 NBC specifies a minimum distance between the exit doors serving the same floor.
Now, the chances that both exits would be blocked at the same time are much lower.
Slide 18
Walking around any building, you'll see a number of doors, but can you tell which are emergency exits?
In fact, often these doors are blocked by, for example, temporary storage, a parked car or snow.
To make it clear which door not to block, the outside of an emergency exit door needs:
- a visible sign, or
- a physical barrier stopping the door from being blocked.
This change was introduced in both the NBC and the National Fire Code (NFC) so it applies to new and existing buildings.
Slide 19
The 2010 NBC only permitted exit doors to have electromagnetic locks.
The 2015 NBC now allows electromagnetic locks on access-to-exit doors with the same unlocking mechanisms as for exit doors.
When your egress path contains more than one electromagnetic lock, once you actuate the first lock, the total release delay should not be more that a total of 15 seconds for all locks encountered.
Slide 20
We hear it in the news regularly - someone has wandered away from their care home - and luck would have it, it's usually during bad weather.
Nursing homes want to use electromagnetic locks but having the doors releasing within 15 seconds is problematic because it can set free residents who shouldn't go out alone.
This 15 second delay is not enough time for staff to react during an unauthorized door opening by a resident.
To balance keeping residents safe and allowing electromagnetic locks in nursing homes, the Code now allows the use of electromagnetic locks without the 15 second delay under a strict set of conditions.
The locking device must automatically release when:
- the alarm signal system is actuated,
- there is a loss of power, or
- the manual fire station located within ½ meter of the door is activated.
Also, within the locked space, a manual switch releasing the locking devices must be accessible by staff in a constantly attended location.
Finally, an emergency lighting system must be installed where these locks are provided.
These changes balance the day-to-day safety needs of nursing home residents with their need to exit safely during a fire event.
Slide 21
There were ways of determining landing sizes in Part 3 and Part 9 of the 2015 NBC, and sometimes, landing size was possibly overly long.
Part 9 determines the size of a landing based on the turning angles, which allows some flexibility
Whereas Part 3 only offered two dimensions - one for straight runs and one for everything else,
For public stairs, the size of a landing that turned less than 90 degrees had to be at least the width of a stair.
This meant unnecessarily long landings for wide staircases.
For example, if the stair was 2 meters wide, the landing was 2 meters long. This situation is less critical in Part 9 buildings as the stairs are usually narrower.
Slides 22-23
The NBC now allows a landing to be at least the width of the stair or 1.1 meters, whichever is smaller.
The Code provides detailed instructions on how this distance is measured, which are highlighted in page 16 of the handbook.
Now for a 2-meter wide stair, the minimum length of the landing would be 1.1 meters.
Whereas for a 1-meter wide stair, the minimum landing would be 1 meter.
These smaller landings:
- use up less floor space, and
- are less expensive to build.
Slide 24
To recap:
Human nature is to return from where you came, so the main entrance in unsprinklered bars and nightclubs now has to accommodate half the occupant load.
Crossover access is no more than two storeys up or down, even below grade.
The exterior discharges of exits have to be further apart and new and existing buildings have to keep the outside of the doors unblocked via signs or barriers.
Electromagnetic locks can be used in care and treatment occupancies.
New way to determine the minimum length of a turning landing.
Slide 25
I have covered a lot of information in today's presentation. The handbook is a useful resource if you want to review the topics from this presentation in more detail.
It covers the majority of technical changes that were implemented in the 2015 National Building Code, National Fire Code, National Plumbing Code and National Energy Code for Buildings.
The handbook can be purchased on NRC's virtual store as a downloadable PDF or as a hard copy.
Slide 26
Contact Information
| Alternative title | Means of Egress (Part 3 of the National Building Code of Canada: 2015) |
|---|---|
| Download |
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| DOI | Resolve DOI: https://doi.org/10.4224/40002101 |
| Author | Search for: 1 |
| Speaker | Search for: Tardif, Patrique1 |
| Affiliation |
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| Format | Video, Learning Object |
| Subject | Codes & guides; construction; building; NRCCode |
| Publication date | 2015 |
| Publisher | National Research Council of Canada |
| Related publication | |
| Language | English |
| Export citation | Export as RIS |
| Report a correction | Report a correction (opens in a new tab) |
| Record identifier | 34f4fa3b-9bb3-41ff-869c-a9b5aaafeca2 |
| Record created | 2021-05-04 |
| Record modified | 2022-06-21 |
- Date modified: