NFPA Journal®, January/February 2005
by Carl F. Baldassarra, P.E.
Like many other cities in the United States, the City of Chicago amended its building code in the mid-1970s to include provisions specifically applicable to new high-rise buildings. The current edition of the Chicago Building Code (CBC) defines high-rise buildings as those having a height of 80 feet (24 meters) or more. The high-rise provisions generally require automatic sprinkler systems, standpipe systems, occupant and fire department voice communication systems, stairway unlocking systems and other passive and active systems similar to the provisions found in the model building codes.
However—again, like many other cities—the issue of fire safety in existing high-rise buildings has been a challenge. In response to a multiple-fatality fire in the Cook County Administration Building on October 17, 2003, Chicago officials considered a number of proposals and began development of an ordinance to address fire safety for an estimated 1,300 existing high-rise buildings in a comprehensive manner. The objective of the ordinance was to provide a reasonable level of safety for the occupants of high-rise buildings and to do so in an economical manner that sustains the city’s economic strength and preserves jobs and business opportunities. Schirmer Engineering Corporation assisted the city staff in reviewing the criteria in the national model codes; reviewing the experience of other cities and jurisdictions adopting similar legislation; considering various issues including practicality, effectiveness, experience, new technology, and costs; and in developing the resulting ordinance.
The Chicago Department of Construction and Permits estimates that there are approximately 1,700 high-rise buildings in the city. Of these, approximately 1,300 were built pre-1975 and 400 were built post-1975. Of the 1,300 pre-1975 buildings, it is estimated that 1,100 buildings are primarily of residential occupancy. It is clear that, with the exception of New York, no other US city has the number of high-rise residential buildings and dwelling units as Chicago. In recent years, owners of high-rise buildings in Chicago have been subject to a number of ordinances, which have had a major financial impact upon some of the buildings. These ordinances require: exterior building facade inspections and repairs (1996, 2003), emergency generators (2000) and evacuation plans (2001). Some building owners have reported expenses of millions of dollars to comply with these previously adopted ordinances. Clearly, there is a heightened sensitivity to an additional ordinance, which may require costly fire safety improvements.
The issue of safety for existing buildings is especially difficult because of practical difficulties and costs involved in making improvements in these buildings. In the past, a number of high-rise building fire safety ordinances were proposed, only to fail because of the associated high cost of compliance. A new approach was needed.
Accordingly, the proposed ordinance was limited in its scope to fire protection features judged to be of basic fire safety importance. While some cities elected to essentially require their existing buildings to meet the same fire safety criteria required of new buildings, such was not the case in Chicago. For example, costly smoke control and pressurization systems, supplied by emergency power, were not deemed as minimum required features given automatic sprinkler protection for commercial buildings and the degree of compartmentation included in residential buildings. In addition, certain provisions in the city’s historically tough building and fire codes were relaxed to reduce the cost of installation and, in the case of unsprinklered buildings, to encourage voluntary sprinkler system installations—without materially reducing the reliability or effectiveness of the systems.
A review of the current codes demonstrated that, in some cases, various provisions in the city’s codes evolved in response to a number of long-addressed concerns and, in other cases, the codes were not modified to reflect the use of current technology and materials. Therefore, NFPA standards were used as the basis to allow the use of effective, reliable, and more economical installations of fire protection systems.
As a result of the reviews and ordinance development in conjunction with city staff, a draft ordinance was developed and posted on the city’s Web site. A number of public hearings were conducted, and the ordinance was subsequently revised. The ordinance was adopted by the City Council on December 15, 2004.
The resulting ordinance provides a reasonable balance between safety and the costs, and consists of the following major elements:
The major elements included in the ordinance are discussed in greater detail in the following sections.
The proposed ordinance will require the owners of all high-rise buildings to file electronic copies of evacuation plans for each building with the city’s 911 Center. The evacuation plans are to include typical floor plans to facilitate on-site search and rescue operations by communication with the 911 Center personnel. The city is also studying technology to allow the display of the information in fire department vehicles on the fire ground in the near future.
Stairway Door Locking
Prior to October 2003, a number of pre-1975 high-rise buildings maintained locked doors from the stairway side of the stair enclosure in the interest of building security. While prohibited for high-rise buildings constructed after 1975, the Chicago Building Code was silent on the application of such requirements in pre-1975 buildings. Shortly after the fire and before the development of a comprehensive draft ordinance, the Chicago City Council adopted an ordinance that prohibits stairway doors locked against re-entry into the building unless such doors are equipped with automatic and manual unlocking systems. As a temporary measure, the ordinance allows locked stairway doors on up to four intervening floors, based upon the provisions in NFPA 101®, Life Safety Code®, but only until January 1, 2005.
Voice Communication Systems
Human behavior studies indicate that it is important to provide timely and accurate information and instructions to building occupants, particularly in the post-September 11 era. The current Chicago Building Code (CBC) criteria for new high-rise buildings require one-way voice occupant notification systems in public areas and in office tenant spaces over 5,000 square feet (465 square meters). In addition, the current criteria for new high-rise buildings require two-way communication systems for fire department use. Costs for these systems were judged to be reasonable when viewed on a per dwelling unit-basis for residential buildings and on a per square foot basis for commercial buildings.
As a means of lessening the financial impact upon residential building owners, no voice systems are required in existing fully sprinklered non-transient residential buildings, and two-way voice systems are not required in non-transient residential buildings that contain fewer than 15 or fewer stories and 60 or fewer dwelling units. In addition, the ordinance includes performance-based language that permits other existing voice communication systems to be used in non-transient residential buildings, provided that the systems meet certain criteria and are judged to be acceptable by the fire department. The ordinance allows a seven-year installation period for the voice systems.
To facilitate the installation of the voice communication systems and fire detection systems associated with the sprinkler systems, a number of modifications were made to the existing provisions of the CBC to allow more economical installations and encourage protection systems above the minimum code requirements. For systems installed as a result of this ordinance only, the modifications allow the installation of low-voltage electrical risers associated with fire alarm and communication systems within stairway enclosures, greatly facilitating the installation in existing buildings.
The CBC also reflected a degree of conservatism in that, for new construction, detection system wiring and notification system wiring cannot be run in the same electrical conduit and the equipment cannot be installed in the same equipment enclosure. The ordinance recognizes wiring methods and listed equipment per NFPA 72, National Fire Alarm Code®, greatly reducing the cost of installations. In addition, the ordinance allows the central station monitoring to be accomplished using digital alarm communication equipment per NFPA 72, not currently approved in the city.
The above modifications have been estimated to save as much as 25 percent of the installation cost of the detection and communication systems over the traditional installation methods.
Automatic Sprinkler Protection
The benefits of automatic sprinkler protection are well -known to city officials and need not be repeated here. While the frequency of fatal fires in high-rise commercial buildings was low, the large numbers of persons in commercial high-rise buildings, the nature of the occupancy and typical building geometries were judged to present an unacceptable risk. On the other hand, an ordinance mandating sprinkler protection in a large number of residential buildings, costing hundreds of millions of dollars, was not considered necessary because of the non-transient nature of the occupants and the inherent level of compartmentation in residential buildings. A review of high-rise residential building fire records, in fact, showed a high degree of the buildings’ ability to limit fires to the unit of origin. Buildings designated as landmarks were also considered to present practical difficulties and, therefore, were exempted from the draft ordinance. Nevertheless, there was a concern about verifying that the residential and landmarked buildings’ construction integrity has been maintained since originally constructed.
The ordinance mandates the installation of sprinklers in high-rise buildings, with the following exceptions: open-air parking facilities, open-air portions of stadiums, non-transient residential buildings, designated landmark buildings and contributing (landmark) buildings. The requirement for sprinklers affects almost all commercial buildings in the city. Knowing the concerns of the real estate industry expressed in previous considerations of a retrofit ordinance, the ordinance was drafted to allow a 12-year installation period, providing that one-third of the installation is completed in each of three four-year incremental periods. A plan of compliance is required to be submitted to the city within one year.
Again, it has been estimated that there are approximately 1,700 high-rise buildings in the city. A survey conducted by the Building Owners and Managers Association (BOMA), which represents 269 commercial buildings and 94 percent of the commercial square footage in Chicago, identified 87 buildings, representing approximately 24.7 million square feet (2.3 million square meters), as being affected by this provision. Most of these buildings are Class B and Class C buildings, an industry term reflecting that they are not the newer, higher rental-rate properties, making it difficult for the property owners to raise rental rates to amortize the cost of the sprinkler installations. BOMA-Chicago estimated that there is a total of 35 million square feet (3.2 million square meters) of unsprinklered office space in the city, 17 million square feet (1.5 million square meters) of which may require asbestos abatement. It was also noted that sprinkler retrofits frequently involve much more than the cost of the sprinkler system alone. For example, a major sprinkler retrofit installation will involve substantially upgrading or replacing the building’s fire-alarm and supervisory system, which monitors the sprinkler system, possibly triggering a further upgrade to comply with Americans with Disabilities Act.
The city has, over the years, enforced certain installation practices, which exceed the criteria included in NFPA 13, Installation of Sprinkler Systems. In order to facilitate the required sprinkler system installations, reducing installation costs—and to encourage the voluntary installation of sprinkler protection in the non-transient residential and landmark buildings—amendments to the existing sprinkler design and installation criteria were included in the ordinance.
The current provisions of the CBC require that the building’s fire protection water supply be based upon the sprinkler system demand plus one-half of the standpipe system demand. In existing buildings, this frequently means that the existing standpipe piping and fire pumps are inadequate, requiring replacement. Such replacements also have a “domino effect,” requiring upgrading of the pumps’ electrical service, water supply piping and emergency generator, etc. The ordinance recognizes the water supply as specified in NFPA 13 as adequate for the existing high-rise buildings, in most cases avoiding the costly fire pump and piping replacements.
The ordinance also allows the design of the systems per NFPA 13, with more liberal—yet effective—sprinkler densities than presently allowed in the CBC, the use of extended coverage sprinklers and other listed sprinklers, and all types of listed piping materials. These sprinklers and materials have not historically been approved. The amendments included in the ordinance are expected to save many thousands of dollars in the large commercial buildings without compromising the effectiveness or reliability of the protection, as demonstrated by years of national experience.
Life Safety Evaluation
To address the issue of providing a reasonable level of safety in the non-sprinklered high-rise buildings, the ordinance includes an approach similar to the concept of the “engineered life safety system” included in the Life Safety Code as an alternative to automatic sprinkler protection. The ordinance prescribes that existing high-rise business and residential buildings which are not sprinkleredbuildings that are not sprinklered be subject to a “Life Safety Evaluation (LSE)” to demonstrate that a minimum level of safety is provided. Although certain parameters are discussed in the Life Safety Code, specific criteria for the engineered life safety system are not provided. Nevertheless, the Life Safety Code requires that the LSE be approved by the authority having jurisdiction having jurisdiction approve the LSE.
The definition of an LSE specifically for existing non-sprinklered residential and landmark commercial buildings first required that an objective be specified with respect to the desired level of safety. After due consideration, a policy decision was made to establish the minimum level of safety consistent with the provisions in the Chicago Building Code specifically applicable to existing buildings. It was the collective judgment of the team that rigorous compliance with the CBC provisions for existing buildings would provide a reasonable level of fire safety. From this review, it was later determined that the CBC requirement for minimum fire resistance rated stairway enclosures in residential buildings was not clear and that a revision to clarify the requirement was necessary. This minimum requirement was included in the ordinance.
Accordingly, because the CBC requirements differ for residential and commercial high-rise buildings, two LSEs were developed to implement this portion of the ordinance, one for non-transient residential buildings, and one for commercial (landmark) buildings, which need not be sprinklered per the proposed ordinance. The methodologies of conducting the LSEs are similar to the Fire Safety Evaluation Systems (FSESs) included in NFPA 101A, Alternative Appproaches to Life Safety. However, the LSEs were specifically developed to measure the buildings’ level of compliance with the minimum provisions of the CBC under which they were designed and constructed.
Like other FSESs, the LSEs for this application include 18 major parameters: building height; construction type; compartment area; tenant separation; corridor walls; vertical openings; HVAC systems; smoke detection; communication systems; smoke control; number and capacity of the means of egress; dead-end corridors; exit travel distance; elevator controls; emergency lighting; mixed occupancy separation; automatic sprinklers and auxiliary uses. The intention of the LSE is to demonstrate that a minimum level of fire safety is achieved in areas involving fire safety, means of egress and general safety, and to allow alternative methods to achieve compliance if the minimum level of protection is not achieved. It is not intended, however, as a method to circumvent the minimum provisions of the CBC applicable to existing buildings. The ordinance will require that the LSE be conducted by a licensed architect or engineer and that a report be completed within 12 months after the passage of the ordinance. The city is responsible for reviewing and approving the LSE for each building, an objective measure of the relative level of safety of the building. Building owners will have up to seven years to complete repairs in order to achieve compliance with the LSE, or owners can elect to sprinkler the building within the 12-year period.
LSEs were conducted on a sample of existing high-rise buildings. It was determined that certain buildings would not meet the minimum criteria. Certain maintenance-related deficiencies were also noted. It was the collective judgment of the staff and the city’s consultant that the LSE identified potentially life-threatening conditions, as was intended, and that the corrective measures would be substantially less expensive than providing automatic sprinkler protection in the same buildings.
Adopting the Ordinance
The elected officials adopting the ordinance were faced with choices such as: What level of safety is needed for existing buildings? How much are the citizens willing to pay for the improved level of safety? In this case, the proposed ordinance differed from previous, unsuccessful attempts at a high-rise ordinance for existing buildings in that it includes a number of cost-saving provisions, tax incentives, reasonable compliance periods, and alternatives to a blanket requirement for automatic sprinkler installations. The legislative body adopting the ordinance, the 50-member City Council and the mayor, balanced the safety interests of the community against the costs of compliance and reached a consensus that the ordinance should be adopted.
The City Council’s action on this ordinance was a determination of an appropriate balance of fire safety and cost for the citizens of the community in order to provide a reasonable level of safety for the occupants of high-rise buildings.
The process described above brought together the various stakeholders and interests affected by a fire safety ordinance for high-rise buildings. After years of experiencing high-rise fires and fatalities, the proposed ordinance for existing high-rise buildings constitutes a comprehensive, balanced approach to the problem that was finally adopted. The ordinance requires automatic sprinklers for high-rise commercial buildings, reflecting the level of risk associated with large numbers of building occupants and the nature of the occupancies which generally include: higher fuel loads, transient occupants not familiar with their surroundings and building geometries allowing for the continuity of combustibles. The LSE required for non-sprinklered high-rise buildings will demonstrate that a reasonable level of safety is provided for those buildings, as well. The various modifications to the material and installation standards, as well as the tax incentives, are intended to assist building owners in making economic decisions in favor of a greater level of safety.
All stakeholders have benefited from the process. Citizens are provided a greater assurance of life safety in the buildings in which they live, work, and shop. Commercial building owners have benefited by helping shape an ordinance that provides the requisite level of safety, accomplished within reasonable time frames, installation cost reductions and tax incentives.
Residential property owners enjoyed the benefits of fire safety improvements without a mandate for automatic sprinklers, accomplished through application of a Life Safety Evaluation, while installation cost reductions and tax incentives remain available to encourage voluntary installations, city officials have fulfilled their responsibility to provide a reasonable level of safety for the citizens and visitors of the affected buildings.
Carl F. Baldassarra is president of Schirmer Engineering Corporation, a national firm of fire protection engineers. Mr. Baldassarra is actively involved in the model code development process for more than 30 years and serves on many NFPA technical committees. He is a registered professional engineer and a member of NFPA, ICC, and SFPE.
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