11 ms·

A Wicked Problem – The Second Egress: Building a Code Change

74 points by yeknoda 4y ago

hedora 4y ago
So, the complaint is that they don't want to stick a fire door on the back of new buildings, since it would undermine some architectural design purity or something?
- scrumper 4y ago
  The thesis isn't particularly clear but what I think they want is a modification to Canadian building code so that structures up to a certain size don't need a second egress. They want that, I think, because that aspect of code makes it hard to design housing that sits in the middle of the scale between single family homes and high rises. That middle tier of housing seems like it could be important if you consider what NIMBY-ism and a shortage of housing is doing to some cities. I couldn't find out out _why_ a second fire exit makes it hard though. Maybe it's not the door, but the need for an extra stairwell? I'd hesitate to call it pretentious wank just because I don't understand it, so let's just say that the site was clearly not written for a lay audience.
  - henrikschroder 4y ago
    You have to go digging on that site a little bit to get to the why: "The building typology of five to six-storey apartment buildings usually involves a single shared central stair, accessed directly from the street with typically two to four dwelling units per floor. However, because the Ontario Building Code requires two means of egress, mid-rise buildings in Toronto are designed with two exit stairs connected by a common corridor. The result is that mid-rise construction only proves feasible on larger sites where around ten or more units can fit within a typical floor plan to achieve an efficient floor area ratio. Zeidler explains that “this appears to be a reasonable precaution for life safety. However, the life safety of this single stair type in Europe has been equal to, if not better than ours,” due to the fact that the single stair scheme is shared between fewer units. By changing the code requirement for two exit stairs, apartment buildings of midrise height could be designed around a single common stair. For instance, a point-access block, the dominant housing typology in dense urban contexts like Berlin, Paris, or Barcelona, is currently not permitted in Canada." https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem
  - mjmahone17 4y ago
    A big chunk of why is the % of floor area that is used for housing versus “support”. Basically a single stair layout gives you 90-95% floor efficiency, and a double stair is closer to 80-85%. People don’t rent common spaces like stairs, so you can bring the value of a building up by ~10% by allowing each apartment to have only a single exit staircase. Also if a lot is small (like 20ft wide or less), you have to compromise the design. For instance, instead of having full-floor units that get cross ventilation (windows at front and back), you may need to have duplex units that take up 40% of the front or back (so only get one side of the building).
  - RegnisGnaw 4y ago
    Its the second stairwell.
  - monknomo 4y ago
    Requiring two egresses usually means that the building will not have an apartment that spans the width of the building, instead there will be a central hallway to connect every apartment to two stairwells. That central hallway seems small, but it eats a fairly substantial percentage of the footprint space of the building. (elevators and trashrooms are also examples of things that eat a lot of footprint; limiting them for smaller buildings is beneficial for floorplan efficiency) And since people do not like bedrooms without windows, having apartments that don't span the width of a building limits possible floorplans, and drives the apartment design towards studios and 1 bedrooms. The buildings tend to become very wide in order to accommodate enough apartments to make them worthwhile to build, so they tend to use up a high percentage of the lot they are sited on, which reduces greenspace and other resident amennities.
    - nradov 4y ago
      In most areas, the building code explicitly requires a window in every bedroom. This serves as an additional emergency exit, either directly on the ground floor or with assistance from firefighters on higher storeys.
      - bbojan 4y ago
        Ironically, in Toronto, not every bedroom is required to have a window [1]. [1] BCC Ruling No. 14-03-1366: https://web.archive.org/web/20210422142050/http://www.mah.gov.on.ca/Page11347.aspx https://web.archive.org/web/20210422142050/http://www.mah.go...
        jaclaz 4y ago
        And this shows how internationally building codes can be very different. In Italy a room, any room for residential use, not only needs a window, but the window(s) surface must be at least 1/8 or in some cases 1/12 of the floor surface of that room, a windowless room can only be a bathroom (with a compulsory exhaust fan) or a closet/corridor/storage/utility room. But this comes not from fire related laws, but rather from minimal health requirements (natural light, ventilation).
- tlb 4y ago
  Most of the buildings on the page are multistory. A door on the ground floor isn't a big deal, but above that they require fire escape stairs, which are big and ugly and create a section with poor views out the windows.
- scotty79 4y ago
  All examples seem to be about single stairs vs pair of stairs.
  - RegnisGnaw 4y ago
    Which is the key issue. The second set of stairs is needed for the second egress.
- jaclaz 4y ago
  Not really, they are saying that the requirement for a second egress in multi-apartment buildings (which is not only a second fire door, it is also a second stair, etc.) makes too costly/complex mid size buildings. The first image on this page exemplifies the issue: https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem https://freight.cargo.site/t/original/i/9b6f13e0414b47f094ad5d69cbdae47abcf05c3c345c61d79d77670ea6d5be82/MissingMiddleDiagram_CityOfEdmonton.jpg https://freight.cargo.site/t/original/i/9b6f13e0414b47f094ad...
  - twblalock 4y ago
    That sounds fair on the surface, but we manage to build multi-egress buildings all the time in other countries, and if a single stairwell is the only egress a lot of people could die in a fire. Some of these mod-sized buildings are too tall to make jumping out of a window a realistic option. So I’m not really sympathetic to this argument. Unlike some building codes, this one is directly connected to a life and death issue and we have seen what happens in fires where people can’t get out.
    - bombcar 4y ago
      Yeah, it seems to me that we can actually work out the situations involved, and being on the sixth floor of a building with only one fire egress seems undesirable. Perhaps it can be compensated for with various "either two egresses OR each bedroom must be equipped to be fire proof for X minutes" or something, and bring back hook and ladder trucks (arguably which are not used as much because buildings now have multiple egresses when that tall).
      - pessimizer 4y ago
        > each bedroom must be equipped to be fire proof for X minutes This is the kind of absurdly complex regulation that sounds simple, but is a lobbyist's dream. Two exits are easy to know when you've implemented, and easy for regulators to check if you've implemented. A "bedroom" being "fire proof" for X minutes will involve 900 pages of nonsense regulations from which lobbyists have carefully removed anything that will affect their bottom line. "Each bedroom must be equipped to be fire proof for X minutes" was the type of rule that caused the fire brigades to tell people in Grenfell to stay in their apartments, and even more importantly the type of rule that allowed contractors to claim compliance to was sufficient enough that they could use flammable, shit cladding that was illegal in Europe and the US, and install it incompetently (because if the units were "fireproof," who could care?)
- ripley12 4y ago
  This is a snarky low-effort comment. Do better.
henrikschroder 4y ago
Wow, being European and used to single-stairwell multi-story buildings, the North American obsession with fire escapes has always seen weird, and it's super interesting that its codification causes the economy of mid-rises to not work out, which in turn causes the weird housing distribution of North American cities. The "missing middle", that the site is talking about.
- deleted 4y ago
  [deleted]
- synu 4y ago
  I think it comes from the houses being made out of wood instead of brick. Or at least it seems likely comparing houses in the Netherlands and US. The way houses burn is just totally different.
  - henrikschroder 4y ago
    Yeah, that might be a big part of it. I was shocked to discover how flimsy multi-story houses are constructed in North America compared to what I'm used to. Every single apartment I've lived in in Stockholm has had a single stairwell, and it's not something I've ever thought about because no-one thinks of it as an issue. But on the other hand, those stairwells are always concrete and stone and marble, and fire regulations forbid you from storing anything in the stairwells or outside your apartment. Take my current Stockholm apartment, there's a four-storey drop from the balcony to the ground and a single stairwell, which would apparently horrify every North American. But the walls are concrete. The walls between apartments are concrete or drywall. There's four apartments per landing. The apartment doors are made of steel. And the stairwell is empty and marbled, so there's nothing that can burn in the stairwell, and it's very difficult for fire to spread from one apartment to the others. There's no sprinkler system, but I think there's a fire extinguisher on each landing. Not a problem.
    - oivey 4y ago
      If an apartment is on fire between yours and the stairwell and that fire extends to the hallway, then you’re dead, right? If there was a second stairwell on the opposite side then you’d still be able to escape. I’m pretty sure sprinklers have been shown to massively increase fire safety.
barbazoo 4y ago
This is the more interesting link outlining the actual problem: https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem
- AlexTWithBeard 4y ago
  I still fail to understand: is slapping an escape ladder on the side of the house THAT expensive?
- dang 4y ago
  We've changed to that from https://secondegress.ca/Manual-of-Illegal-Floor-Plans https://secondegress.ca/Manual-of-Illegal-Floor-Plans, which is also interesting but better as a secondary url. Thanks!
bearcobra 4y ago
I'm currently remodeling my house and our contractor recommended adding a fire suppression system as part of the project. I always assumed that would be something I couldnt afford but the quote was pretty reasonable (~2500) I wonder if these kinds of systems, plus advances in other building materials have reduced the risk profile to the point where multiple egress points are no longer needed
- dieselgate 4y ago
  Just curious what the "fire suppression system" is in practice, is it sprinklers or specific fire retardant materials (drywall, shingles etc) used. Also wondering what geo location you are in (in consideration of regional fire risks and codes). Edit: would assume single/multiple egress points are tied to the human capacity limit for the building but am not an arch/civil engineer
- xenadu02 4y ago
  Any amount of water you can get onto a fire increases survivability (both in time and number of locations). NFPA 13R is a relatively recent addition to fire code that focuses on making low-rise residential fire sprinklers much cheaper to install and that shows in the price quote you got. 13R allows use of existing plumbing connections. It doesn't require a separate feed from the water main, nor does it require a separate iron pipe network inside the structure. It also doesn't require extensive equipment like some commercial systems do (eg sensing when one sprinkler goes off and using high-pressure to force the whole zone of sprinklers to go off). > advances in other building materials Definitely not. You'd think we would require a quick spray-down of boric acid on wood stick construction right after framing. Boric acid (or borax) is an insect repellant, smolder suppressor, and fire retardant when used this way. It would - at minimum - slow the spread of structure fires. It is also dirt cheap. But nope... buildings themselves are just as flammable today as they were 50 years ago. Survivability is worse thanks to so much synthetic fabric and foam giving off really toxic fumes and more or less no requirement to make anything flame resistant. --- If you want to increase survivability in your own home: 1. If you can afford it have sprinklers installed. In most US states the cost is a lot less than you might think, well under $10k. Usually under $5k. Insurance can't replace lives nor keepsakes. Nor can it repair bodily injury. If you worry about water damage I can promise you repairing it is far cheaper than repairing smoke/fire damage. 2. Have working smoke detectors. Get 10-year sealed lithium ones. The day you install them set a reminder in you phone for 10 years from now to replace them. Install them in the recommended locations. 3. Sleep with your door closed. If you need air, crack a window. If your room doesn't circulate enough from a forced air system shave a bit off the bottom of the door. Experiments show even a cheap cardboard core door can provide 30 minutes of protection from a raging house fire. It blocks most of the smoke. It also greatly slows down heat transfer which reduces flashover risk. I'm not joking - you can find videos on the web where the hallway is a charred black hellscape but the bedding/carpet in a bedroom behind a closed door isn't even slightly blackened.
aaron695 4y ago
[dead]

74 points by yeknoda 4y ago

So, the complaint is that they don't want to stick a fire door on the back of new buildings, since it would undermine some architectural design purity or something?

scrumper 4y ago
The thesis isn't particularly clear but what I think they want is a modification to Canadian building code so that structures up to a certain size don't need a second egress. They want that, I think, because that aspect of code makes it hard to design housing that sits in the middle of the scale between single family homes and high rises. That middle tier of housing seems like it could be important if you consider what NIMBY-ism and a shortage of housing is doing to some cities. I couldn't find out out _why_ a second fire exit makes it hard though. Maybe it's not the door, but the need for an extra stairwell? I'd hesitate to call it pretentious wank just because I don't understand it, so let's just say that the site was clearly not written for a lay audience.
- henrikschroder 4y ago
  You have to go digging on that site a little bit to get to the why: "The building typology of five to six-storey apartment buildings usually involves a single shared central stair, accessed directly from the street with typically two to four dwelling units per floor. However, because the Ontario Building Code requires two means of egress, mid-rise buildings in Toronto are designed with two exit stairs connected by a common corridor. The result is that mid-rise construction only proves feasible on larger sites where around ten or more units can fit within a typical floor plan to achieve an efficient floor area ratio. Zeidler explains that “this appears to be a reasonable precaution for life safety. However, the life safety of this single stair type in Europe has been equal to, if not better than ours,” due to the fact that the single stair scheme is shared between fewer units. By changing the code requirement for two exit stairs, apartment buildings of midrise height could be designed around a single common stair. For instance, a point-access block, the dominant housing typology in dense urban contexts like Berlin, Paris, or Barcelona, is currently not permitted in Canada." https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem
- mjmahone17 4y ago
  A big chunk of why is the % of floor area that is used for housing versus “support”. Basically a single stair layout gives you 90-95% floor efficiency, and a double stair is closer to 80-85%. People don’t rent common spaces like stairs, so you can bring the value of a building up by ~10% by allowing each apartment to have only a single exit staircase. Also if a lot is small (like 20ft wide or less), you have to compromise the design. For instance, instead of having full-floor units that get cross ventilation (windows at front and back), you may need to have duplex units that take up 40% of the front or back (so only get one side of the building).
- RegnisGnaw 4y ago
  Its the second stairwell.
- monknomo 4y ago
  Requiring two egresses usually means that the building will not have an apartment that spans the width of the building, instead there will be a central hallway to connect every apartment to two stairwells. That central hallway seems small, but it eats a fairly substantial percentage of the footprint space of the building. (elevators and trashrooms are also examples of things that eat a lot of footprint; limiting them for smaller buildings is beneficial for floorplan efficiency) And since people do not like bedrooms without windows, having apartments that don't span the width of a building limits possible floorplans, and drives the apartment design towards studios and 1 bedrooms. The buildings tend to become very wide in order to accommodate enough apartments to make them worthwhile to build, so they tend to use up a high percentage of the lot they are sited on, which reduces greenspace and other resident amennities.
  - nradov 4y ago
    In most areas, the building code explicitly requires a window in every bedroom. This serves as an additional emergency exit, either directly on the ground floor or with assistance from firefighters on higher storeys.
    - bbojan 4y ago
      Ironically, in Toronto, not every bedroom is required to have a window [1]. [1] BCC Ruling No. 14-03-1366: https://web.archive.org/web/20210422142050/http://www.mah.gov.on.ca/Page11347.aspx https://web.archive.org/web/20210422142050/http://www.mah.go...
      - jaclaz 4y ago
        And this shows how internationally building codes can be very different. In Italy a room, any room for residential use, not only needs a window, but the window(s) surface must be at least 1/8 or in some cases 1/12 of the floor surface of that room, a windowless room can only be a bathroom (with a compulsory exhaust fan) or a closet/corridor/storage/utility room. But this comes not from fire related laws, but rather from minimal health requirements (natural light, ventilation).
tlb 4y ago
Most of the buildings on the page are multistory. A door on the ground floor isn't a big deal, but above that they require fire escape stairs, which are big and ugly and create a section with poor views out the windows.
scotty79 4y ago
All examples seem to be about single stairs vs pair of stairs.
- RegnisGnaw 4y ago
  Which is the key issue. The second set of stairs is needed for the second egress.
jaclaz 4y ago
Not really, they are saying that the requirement for a second egress in multi-apartment buildings (which is not only a second fire door, it is also a second stair, etc.) makes too costly/complex mid size buildings. The first image on this page exemplifies the issue: https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem https://freight.cargo.site/t/original/i/9b6f13e0414b47f094ad5d69cbdae47abcf05c3c345c61d79d77670ea6d5be82/MissingMiddleDiagram_CityOfEdmonton.jpg https://freight.cargo.site/t/original/i/9b6f13e0414b47f094ad...
- twblalock 4y ago
  That sounds fair on the surface, but we manage to build multi-egress buildings all the time in other countries, and if a single stairwell is the only egress a lot of people could die in a fire. Some of these mod-sized buildings are too tall to make jumping out of a window a realistic option. So I’m not really sympathetic to this argument. Unlike some building codes, this one is directly connected to a life and death issue and we have seen what happens in fires where people can’t get out.
  - bombcar 4y ago
    Yeah, it seems to me that we can actually work out the situations involved, and being on the sixth floor of a building with only one fire egress seems undesirable. Perhaps it can be compensated for with various "either two egresses OR each bedroom must be equipped to be fire proof for X minutes" or something, and bring back hook and ladder trucks (arguably which are not used as much because buildings now have multiple egresses when that tall).
    - pessimizer 4y ago
      > each bedroom must be equipped to be fire proof for X minutes This is the kind of absurdly complex regulation that sounds simple, but is a lobbyist's dream. Two exits are easy to know when you've implemented, and easy for regulators to check if you've implemented. A "bedroom" being "fire proof" for X minutes will involve 900 pages of nonsense regulations from which lobbyists have carefully removed anything that will affect their bottom line. "Each bedroom must be equipped to be fire proof for X minutes" was the type of rule that caused the fire brigades to tell people in Grenfell to stay in their apartments, and even more importantly the type of rule that allowed contractors to claim compliance to was sufficient enough that they could use flammable, shit cladding that was illegal in Europe and the US, and install it incompetently (because if the units were "fireproof," who could care?)
ripley12 4y ago
This is a snarky low-effort comment. Do better.

henrikschroder 4y ago

Wow, being European and used to single-stairwell multi-story buildings, the North American obsession with fire escapes has always seen weird, and it's super interesting that its codification causes the economy of mid-rises to not work out, which in turn causes the weird housing distribution of North American cities. The "missing middle", that the site is talking about.

deleted 4y ago
[deleted]
synu 4y ago
I think it comes from the houses being made out of wood instead of brick. Or at least it seems likely comparing houses in the Netherlands and US. The way houses burn is just totally different.
- henrikschroder 4y ago
  Yeah, that might be a big part of it. I was shocked to discover how flimsy multi-story houses are constructed in North America compared to what I'm used to. Every single apartment I've lived in in Stockholm has had a single stairwell, and it's not something I've ever thought about because no-one thinks of it as an issue. But on the other hand, those stairwells are always concrete and stone and marble, and fire regulations forbid you from storing anything in the stairwells or outside your apartment. Take my current Stockholm apartment, there's a four-storey drop from the balcony to the ground and a single stairwell, which would apparently horrify every North American. But the walls are concrete. The walls between apartments are concrete or drywall. There's four apartments per landing. The apartment doors are made of steel. And the stairwell is empty and marbled, so there's nothing that can burn in the stairwell, and it's very difficult for fire to spread from one apartment to the others. There's no sprinkler system, but I think there's a fire extinguisher on each landing. Not a problem.
  - oivey 4y ago
    If an apartment is on fire between yours and the stairwell and that fire extends to the hallway, then you’re dead, right? If there was a second stairwell on the opposite side then you’d still be able to escape. I’m pretty sure sprinklers have been shown to massively increase fire safety.

barbazoo 4y ago

This is the more interesting link outlining the actual problem: https://secondegress.ca/A-Wicked-Problem https://secondegress.ca/A-Wicked-Problem

AlexTWithBeard 4y ago
I still fail to understand: is slapping an escape ladder on the side of the house THAT expensive?
dang 4y ago
We've changed to that from https://secondegress.ca/Manual-of-Illegal-Floor-Plans https://secondegress.ca/Manual-of-Illegal-Floor-Plans, which is also interesting but better as a secondary url. Thanks!

bearcobra 4y ago

I'm currently remodeling my house and our contractor recommended adding a fire suppression system as part of the project. I always assumed that would be something I couldnt afford but the quote was pretty reasonable (~2500) I wonder if these kinds of systems, plus advances in other building materials have reduced the risk profile to the point where multiple egress points are no longer needed

dieselgate 4y ago
Just curious what the "fire suppression system" is in practice, is it sprinklers or specific fire retardant materials (drywall, shingles etc) used. Also wondering what geo location you are in (in consideration of regional fire risks and codes). Edit: would assume single/multiple egress points are tied to the human capacity limit for the building but am not an arch/civil engineer
xenadu02 4y ago
Any amount of water you can get onto a fire increases survivability (both in time and number of locations). NFPA 13R is a relatively recent addition to fire code that focuses on making low-rise residential fire sprinklers much cheaper to install and that shows in the price quote you got. 13R allows use of existing plumbing connections. It doesn't require a separate feed from the water main, nor does it require a separate iron pipe network inside the structure. It also doesn't require extensive equipment like some commercial systems do (eg sensing when one sprinkler goes off and using high-pressure to force the whole zone of sprinklers to go off). > advances in other building materials Definitely not. You'd think we would require a quick spray-down of boric acid on wood stick construction right after framing. Boric acid (or borax) is an insect repellant, smolder suppressor, and fire retardant when used this way. It would - at minimum - slow the spread of structure fires. It is also dirt cheap. But nope... buildings themselves are just as flammable today as they were 50 years ago. Survivability is worse thanks to so much synthetic fabric and foam giving off really toxic fumes and more or less no requirement to make anything flame resistant. --- If you want to increase survivability in your own home: 1. If you can afford it have sprinklers installed. In most US states the cost is a lot less than you might think, well under $10k. Usually under $5k. Insurance can't replace lives nor keepsakes. Nor can it repair bodily injury. If you worry about water damage I can promise you repairing it is far cheaper than repairing smoke/fire damage. 2. Have working smoke detectors. Get 10-year sealed lithium ones. The day you install them set a reminder in you phone for 10 years from now to replace them. Install them in the recommended locations. 3. Sleep with your door closed. If you need air, crack a window. If your room doesn't circulate enough from a forced air system shave a bit off the bottom of the door. Experiments show even a cheap cardboard core door can provide 30 minutes of protection from a raging house fire. It blocks most of the smoke. It also greatly slows down heat transfer which reduces flashover risk. I'm not joking - you can find videos on the web where the hallway is a charred black hellscape but the bedding/carpet in a bedroom behind a closed door isn't even slightly blackened.

aaron695 4y ago

[dead]