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High rise buildings associated safety and services issues

In January 2014, under the stewardship of the past regime, the Chairman, Sri Lanka Ports Authority announced that associated with the new Colombo Port City, Sri Lanka’s first 100 storied skyscraper was expected to be constructed in the city. In July 2015, under the stewardship of the present regime, the Board of Investments announced that the tallest building in the country, comprising of ground plus 96 floors with a height of 363 meters and having 376 residential apartments, 92 pent-houses and other modern amenities will be constructed as a high rise iconic tower.

National Fire Prevention Association, in its website http://www.nfpa.org/ states that

“High-rise buildings present several unique challenges not found in traditional low-rise buildings; longer egress times and distance, evacuation strategies, fire department accessibility, smoke movement and fire control. The multiple floors of a high-rise building create the cumulative effect of requiring great numbers of persons to travel great vertical distances on stairs in order to evacuate the building.

High-rise buildings have garnered significant attention in the fire safety world over the years. The public, code bodies, local, regional and federal governments, as well as the design, build, and ownership communities are all affected by high-rise building safety”.

(A copy of a note extracted from the web, titled “Fire Safety in High Rise Buildings” is given below).

In view of the safety issues highlighted above, shown to affect not only the users and occupants of such buildings but also the community at large, it is essential that the Ministry engaged in the promotion of investments, the Municipality of Colombo and the Urban Development Authority accountable for the provision of essential fire safety and other associated essential services to the high rise buildings, explain to the civil society, what steps they have collectively taken to ensure that the long term sustainable provision of such essential services will be available, including;

I would therefore appeal that a ‘white paper’ be presented for public awareness, review and discussion on the “Way Forward in Effectively Managing the Future Challenges of High Rise Buildings Associated Safety and Services Issues’.

C. Jayaratne ,Colombo 5

Fire safety in high rise buildings

Buildings over 20 metres in height create specific challenges for firefighters, with accompanying hazards for building occupants. Indeed, firefighters cannot reach the upper stories from the building exterior for firefighting or rescue operations, while interior fire incidents are hampered by distances that need to be climbed with heavy breathing apparatus and equipment.

Furthermore, the sheer size of high-rise buildings and large number of people within make it impractical to immediately evacuate during an emergency. Fixed fire protection features must be in place to automatically detect and control fires, so that occupants can remain in a building for a given period of time at a safe distance from a fire.

Exactly why is the threat of fire perceived to be so much greater in high-rise apartment buildings? Some of the main reasons are listed below :

Egress Systems

There is considerable potential for crowding and slow movement on exit stairs in high buildings because of the number of floors and because these stairs do not normally increase in width as they descend, Stair shafts are also one of the primary means by which smoke moves vertically. In addition, the higher the building, the longer it takes occupants to descend the stairs, thus increasing the potential for smoke exposure. A building egress system must therefore provide sufficient evacuation time before smoke reaches lethal levels and harms those still inside.

Fire Department Access

Even with modern aerial apparatus, fire services can still only reach six or seven floors of a building, so exterior rescue and firefighting operations are restricted to the lower floors. With fires above this level, firefighters must move vertically inside the building and fight the fire at the same time as occupants are descending the stairs. This can result in delays in reaching and attacking a fire, as well as increased contamination of stair shafts if doors to exits are left open to run hoses.

Forces Of Nature

Stack effect and winds have a major impact on the movement of smoke in high buildings, and tend to be worse the higher the building. Wind velocity and direction also affect the course of a fire, but are significantly less of a problem in lower buildings.

Increased Density Of Occupants And Fuel Load

With a greater number of floors in a building, occupant and fuel densities inevitably increase. Despite horizontal fire barriers, fire moves in an upward direction, thus potentially adding more fuel and affecting more occupants.

Complex Vertical Utility Services

High-rise buildings contain a complex series of pipes, ducts, cables and conduits running vertically. Fire protection water supplies must also be provided from either the top or bottom of the building – both with associated problems. These vertical utilities often generate other issues, such as fire system cables being damaged by fire on one level and affecting many other floors.

Integrated Fire Problems

High-rise apartment buildings are no longer standalone structures, but often situated above shopping malls or other commercial premises, over atrium buildings containing offices, or on top of underground systems. Each occupancy has to contend with its own unique set of fire safety issues. Coupled with those of a high-rise apartment building, these problems require specially engineered solutions to ensure occupant safety.All these unique features represent specific challenges to be addressed before a fire-safe high-rise design can be achieved. While codes and standards provide generalised solutions to many of the problems, architects must be aware of the problems and the need for tailored solutions based on sound fire safety engineering.