As the issue of access for people with disabilities in buildings is being widely promoted in recent times, the question of ‘equal egressibility’ for all in emergency situations is also made more acute. Combined with an ageing population, the proportion of building users with some forms of physical, sensory (hearing and seeing) or mental capacity in high rise built environment cannot therefore be underestimated. The incapability of providing egress for people who either have difficulty or downright impossible to use exit stairs in the event of a major evacuation when lifts were considered unsafe increase the risk factors of injuries and fatalities to this group of evacuees. Such egress deficiency in buildings continues to be a basic ethical problem. Should equal access right be also extended to an equal right of emergency egress in future building designs – especially in all tall buildings and public buildings where people are gathered in large numbers?
Introduction
In general, the community is of the belief that the authorities will require a sufficient level of fire safety to ensure they are safe when they enter buildings and that they can also get out quickly during building emergencies. Hence, most modern codes around the world have specific requirements to address various aspects of providing adequate access/egress to all buildings. For examples, Building Code on ‘Barrier-Free Accessibility in Buildings’ that requires buildings to make more accessible to the disabled and the elderly; protected staircases are legal in many jurisdictions, but no jurisdiction guarantees that everyone has the physical ability to walk down the stairs unaided. The codes have very little guidelines about emergency egress for the disabled once they have made it in.
In short, the codes make no requirement for multi-story buildings to provide alternative means of escape for those people who are unable to walk down the stairs during emergency. Clearly, the shortcomings in the building egress systems raises an assortment of moral issues, but also some more practical difficulties. No body should be left behind; people with mobility limitations should have equal access to building evacuation. The fire service may be engaged elsewhere and they cannot guarantee arrival within a specific time. The firefighters have limited resources with which to focus on fighting the blaze and also of searching for victims.
Building Egress Systems (Exit Stairs and Refuge Areas)
Special access features such as, ramps to provide wheelchair accessibility, lifts control panel lowered within the reach of the wheelchair-bound and lift landings at every floor of tall buildings have make buildings more accessible to the disabled and the elderly. However, we must also address the emergency egress inside the building. Once the disabled have made it in, how to get them out quickly during building emergencies when elevator evacuation unavailable. Until recently, the disabled people have to rely on assisted evacuation to get them out of the building in total evacuation. As a result, fire safety for the disabled has become a multi-faceted challenge for building managers.
Prompted by the need to address the different problems faced by people with disabilities in emergency situations, modern buildings provide visual and audio emergency notification system, automatic sprinkler protection system and areas of refuge on each floor of tall building. In typical fires, these protection features are considered to be more than adequate to provide the “Defend in Place” strategy allowing those who have difficulties in using stairs to stay in temporary refuge areas until the fire has been eliminated or rescue arrives. Hence, nearly every high-rise building has not been designed to ensure that everyone in a tall building has an equal opportunity to get out quick in a full extreme emergency evacuation. Yet, the ability to empty the total building population in the shortest possible time is critical under life threatening emergency situations.
Currently, building requirements for exit stairs are designed to ensure that, for building users in general, adequate means of escape are built into the structure. However, the complication is that these arrangements devised to cater for general occupancy might not be suitable for the elderly and people with disabilities in certain situations. Yet, the only safe way out of a high rise building in an emergency is down the exit staircase.
The potential for major incidents in tall buildings is, thankfully, low. But when they do occur, not all people can be expected to get out of a building by their own unaided efforts. The prompt evacuation of these people may just totally reliant upon the effectiveness of the building design, the comprehensiveness of evacuation procedures, as well as the adequacy of emergency response staff and occupant training.
The idea of using firemen’s lifts for evacuation of any mobility-impaired persons creates a conflict of interest as to what a fireman’s role should be. Such lifts are meant for firemen to move their equipment and themselves quickly up to the location of fire and fight it. Another concern is the difficulty of controlling other able-bodied people from using firemen’s lifts when they know that it is a quicker means of getting them down to the ground in a fire situation.
Problems in Stairs Evacuation
While exit stairs in tall buildings are designed to accommodate total building evacuation, there are practical matters associated with always having to empty the total building. The ideal plan of building occupants moving in an orderly manner toward and down the fire stairs is an option only available to the able-bodied. The general population in a high rise has approximately 30% of building occupants with some degrees of disadvantages regarding the use of stairways in emergency evacuation.
Evacuating multiple floors of a high-rise building creates the cumulative effect of requiring great numbers of people including those who need assistance to travel great vertical distances on stairs. For everyone, but particularly those with limited mobility rely on assisted evacuation, time is crucial. The generic evacuation activities necessary for people with disabilities to reach a safe place are essentially the same as that of able-bodied persons. However, the duration needed to execute each of these activities is a function of individual capability. Ambulatory elderly and children are slower to evacuate and may adversely affect their own and other occupants’ evacuation time. People with permanent disabilities may not be able to evacuate at all. Temporary incapacitation - use of crutches, a leg cast or foot braces - will also inhibit evacuation.
Evacuation Time
The myth of evacuation time taken to empty a tall building during a fire drill cannot be a determine factor of how long it will take to evacuate the structures under actual emergency situations. Typically, evacuation does not begin until occupants smell smoke or hear a human voice ordering them to immediately leave the building. In addition, the firefighters will have to walk up the same stairway that contain fleeing occupants, not only slowing down their response time to reach the fire zone but also slowing down the stairs evacuation process. The physical demands made on high-rise occupants exiting in stairwells can exceed their capabilities in actual emergencies. It will take more hours to safely move all the people out of a blazing high rise than during a fire drill. Yet, in extreme high rise emergencies, the ability to get as many people out of a tall building before the arrival of firefighters is crucial to safe evacuation -- making time an ally
Future Tall Buildings
Sustainability, Mobility and Identity are without doubt the three critical considerations determining how buildings of tomorrow are designed and constructed. The buildings of tomorrow will not be complete without the designed for accessibility as well as egressibility for every person to get out during emergency evacuation.
The future tall buildings belong to building community who see the need to provide equal access and egress into the structure as different people have different capabilities and limitations during emergency evacuation. While it is unfair to say that these buildings are ‘unsafe’ when it comes to the evacuation of people with disabilities, these people would definitely benefit from more tactful building design to provide alternative means of getting the disadvantaged to the ground floor more quickly and safely.
Given that lifts are unsafe to use in emergency, stair travel is taxing and potentially dangerous for the aged and the disabled: What if the concept of equal access right be extended to an equal right of emergency egress in future tall building designs? What if high-rise buildings to be designed to allow for a full extreme emergency evacuation? What if future multi-storey buildings to provide enhanced vertical transportation system that can be used by all people, including the severe mobility impaired during building emergencies? What if high-rise buildings will to reserve stairway(s) or fireman’s lifts for fire fighters priority use during building emergencies so as to enable them to reach the fire zone more quickly and also faster for them to get out if the situation got worse?
The transient difficulties in making changes for future building design with a focus on increasing the performance of tall buildings include emergency egress subject to extreme events are far outweighed by the immeasurable benefits to fire departments and to both able-bodied and mobility-impaired building occupants. To try to get out of a building menaced of smoke invasion or structural impairments is the only acceptable way to guarantee the most efficient life safety prevention.
Technology and Innovation
When it comes to equal egress for all in an emergency, many countries have long recognised the difficulties of moving people with disabilities out of high rise through exit stairs. In search for suitable measures to meet the evacuation needs of tomorrow, much good work detailing the various options for the safe evacuation of people with disabilities has been produced in recent years.
For instance, since 1982, the concept of escape chute evacuation has been considered a fast and safe vertical transportation method that provides mobility impairment peoples a protected way out of building even when elevator evacuation has been considered unsafe for use in extreme emergencies. Although current fire regulations do not require buildings to provide such a facility for escape or rescue purposes, however, building owners in many countries have installed escape chute to supplement stairs to meet their evacuation requirement. It is estimated that over a million of people have tested the escape chute evacuation from two stories to high rise.
The escape chute works on the principle of gravity, using the stress and friction method. Usability for all people, regardless of body size, shape and weight, injured on stretcher and unconscious people can use the chute. Once inside the chute the evacuee will arrive at ground level quickly and relatively safely. It offers worry-free solution and reduces the risk of injury to the disadvantaged who have difficulty or have no ability to use stairs in getting out of the building.
Complementary Means of Escape
Escape chute evacuation system is an emergency exit, permanently fixed to a location and is always ready for use within seconds. It needs no power-supply to operate, allowing it to be operational for evacuation during a power outage, act as a nearly fail-safe vertical transportation system where some other vertical egresses leave off in an extreme emergency situations. There are several types of escape chutes:
Multiple-Entry: The multiple escape chute system is installed inside a protected vertical shaft enclosure in new building or retrofitted in existing building. The installation is constructed in accordance to local fire code that provides protection from fire effects for evacuees so that it can be used safely for emergency egress. The chute is permanently available at each level inside the fire-protected shaft, one segment of chute per floor, from the highest floor to the ground floor on the same vertical line with no length and height constraints. Evacuation takes place inside the building and occupants can gain access to the chute at each floor where several levels can be simultaneously evacuated.
Accessible Means of Escape Design: This emergency egress design is a unique and integral part of the enhanced staircase development of vertical exits in tall buildings. It requires the ability of incorporating the facility of multiple escape chute system inside the enhanced staircase enclosure. When fire occurs, the disabled and the severe mobility impaired will have to make their way, assist or unassisted, and take temporary refuge inside this stair enclosure while waiting for rescue. They can either choose to use the chute inside the stair enclosure that would get them to the ground floor more quickly and relatively safely or to be assisted by helpers down the stairs.
Single-Entry: This one entry chute installed in old or existing building whereby there is no possibility of incorporating the Multi-Entry chute. Each chute installation at window, balcony, rooftop, best serves the occupants of that particular floor. This exterior chute is constructed of 3 layers, the outer layer is fire resistant – protects the chute against flames, the middle layer provides a speed restraining effect, and the inner layer supports the whole weight of chute. This 3-way protection protects the evacuees once inside the chute from fire, heat, and smoke during evacuation.
Movable: This portable chute has become standard rescue equipment for sky-lifts used by fire brigades worldwide for high rise rescue operations. The chute is constructed of 3 layers, and this 3-way protection protects the evacuees once inside the chute from fire, heat, and smoke during rescue operation.
With the escape chute, evacuees might easily deliver themselves to safety within a few precious seconds at a time during which those few precious seconds may make all the difference. The used of escape chute and exit stairs together to accommodate mass building evacuation, would take much lesser time to empty the total building population, simultaneously, allowing the occupants evacuation right, and the fire fighting priority, making high rise evacuation quicker and relatively safer.
Cost Of Making Buildings Egressible
What the exit stairs worked well for emergency evacuation in the past is no longer adequate under the present global ageing environment. Given that the accessible means of escape is above the required minimum of an exit staircase, it should not be considered as an unnecessary increase in the cost of the building project, through which people with disabilities and the able-bodied people can leave the building in an emergency. It offers lesser worry solution to Developers, Building Owners, Building Managers, occupants and visitors in the event of a major evacuation, and reduces the risk of injury to the disadvantaged who have difficulty or have no ability to use stairs in getting out of the building.
Planning and incorporating such egress features in buildings now to meet the evacuation needs of tomorrow will avoid having to correct the egress deficiencies after the building has been built. It is often easier and more cost effective to plan and incorporate such means of emergency egress at the building design stage than when the building is constructed. The cost incurred accounts for a very small percentage of the total cost of the new construction, upgrading or renovation, and operations of the building.
Conclusion
Following the terrorist attacks on the World Trade Centre twin office towers and the Pentagon in the United States in September 11, 2001, it has become clearer that all people must be able to get out of tall building quickly in case of extreme emergency. People with disabilities who work or live in a high-rise building at an elevation that is beyond the reach of fire-fighting or rescue apparatus, their best hope for an emergency escape might not be found in the crowded or smoke-filled stairwell. By using the latest technology and the development of applicable codes and standards, it is possible to adopt new solutions to provide the disabled people the same ability that able-bodied people have for vertical exits, making future tall buildings egressible to everyone.
For more information on the escape chute evacuation – please visit our web-sites: www.escapeconsult.com or www.algonet.se/~ingstrom/ or email us at: mobiltex@singnet.com.sg for more details.
