Kerwin Lee, AIA, CASp
Oakland Construction Site Fire, Alta Waverly – The most recent fire in Oakland shows the vulnerability of buildings under construction. They are easy targets for a catastrophic fire. There have been several major fires in the Bay Area associated with buildings under construction: Santana Row, 2002, San Francisco, China Basin 2014, and Emeryville 2016. All of these were wood framed construction with just the framing up. Fortunately in all of these cases, there was no loss of life. So how does one protect a structure under construction?
Chapter 33 of the California Building Code addresses safety during construction. Also, NFPA-241, which is referenced in the code, is the Standards for Safeguarding Construction, Alterations and Demolition Operations. This would include hazard awareness, ignition prevention and fire protection during construction, mainly water supply and fire department access. The most common cause of construction site fire is associated with “hot work” like welding and grinding of metal. But when it is arson, the code is silent. This becomes a security issue.
Grenfell Tower, London – It is still too early to draw any conclusions from this fire and what went wrong, but the first thing people ask is can this happen in the USA? This should not happen if the construction follows the building codes. Our code, for about the last 20 years, does not permit, or at least limits, combustible construction on or in high-rise buildings. High-rise buildings continue to be the safest type of construction we have. There are a lot of questions about whether there was an operating fire alarm and sprinkler system in the Grenfell Tower.
One of the discussion lines has been on the egress approach and whether shelter in place is appropriate. The standard for evacuation of a high-rise building associated with a fire is to alarm the floor below and two floors above. Setting off the fire alarm system for the entire building would overwhelm the egress system (enclosed stairs). It has been calculated and tested through evacuation drills that for a large high-rise it could take hours to evacuate the entire building. If and when there are high-rise fires, they are usually contained to the floor of origin by the sprinkler system. So this methodology does work. If for any reason the fire expands, the fire department will make the call to expand the evacuation if necessary.
There are many other evacuation options now used, including the use of elevators for evacuations. When the fire department deems it necessary to use the elevators for evacuation, it should be in a logical and orderly manner. Since this approach has never been tested in a true emergency to my knowledge, how it works has a lot of unanswered questions. Who get the use of elevators first? How does one know to use the elevators and how do you know when? People are not going to just wait in the elevator lobby.
When evacuation is required, the most vulnerable people are the ones with disabilities. They really have to depend on the shelter in place concept. A visually impaired person would have a tough time finding the exits alone. There is no simple answer to all of these situations. The best is knowledge of your surroundings and having a plan for self preservation. This is most important for people with disabilities.
Erick Mikiten, AIA, LEED-AP
When we’re designing complex buildings, Means of Egress should be one of the first things we start with. This doesn’t sound exciting, but understanding the basic needs of how to get your building’s occupants out of various spaces and to the Public Way will create the framework for your entire design. There’s nothing worse than getting a great schematic design together, then realizing you don’t have enough exit stairs, or that another rated corridor is needed right where you wanted something else to happen.
One of the benefits of having that framework early is that you can incorporate the ideas of an Accessible Means of Egress well, per Section 1009 of the CBC. This can be a philosophically vexing issue. On the one hand, the ability to exit the building the way you came in is ideal. This is cognitively clear, and in an emergency situation, clarity is critical. But for people with disabilities in a multistory building that often means elevators and the front door.
But what if it’s an older building and that front door is the only accessible entrance and exit? Then someone with a disability might be confronted with stairwells, rated corridors, and stairs at a side or rear exit door. That can be a pretty terrible situation in the midst of a chaotic evacuation during an earthquake or fire. So what to do?
Well, if you think about exiting early on, you’ll have a fighting chance to incorporate better accessible means of egress into your design. So maybe that second exit on the side of your building, with a couple of steps, can be designed with none. Then all people can use it’s impossible to use the accessible entrance lobby. When we are providing Areas of Refuge in stairwells (Section 1009.3), think about larger wheelchairs and the possibility of having more people in wheelchairs than the code requires. Or someone might have an attendant with them who wants to stay in that space. So make that space larger than the minimum so that that a larger electric wheelchair, or an attendant with someone in a wheelchair, isn’t in the way of the rest of the occupants going down the stairwell.
And when you do introduce an exit component such as an Area of Refuge or Exterior Area for Assisted Rescue (Section 1009.7), take particular care to make your signage extra clear, since the layperson with a disability is generally not aware of these code devices. That will make your buildings safer, more usable, and help everyone exit them in an orderly fashion when needed.