New Guide on Fire Safety in Very Tall Buildings

Issue 60: New Guide on Fire Safety in Very Tall Buildings

By James R. Quiter, P.E., FSFPE

The Society of Fire Protection Engineers is in the final stages of developing a new engineering guide, entitled " Fire Safety for Very Tall Buildings” The draft document was issued for public comment in February, and over 150 comments were received. The Task Group that is creating the document met in July and has responded to those comments. The next step is for the Task Group to finalize the document and submit to the Technical Steering Committee for approval, with a goal of being published in early 2013.

The document is a joint effort of SFPE and the International Code Council (ICC). Both organizations solicited members for the Task Group, and the process began in 2010. Since that time, the Task Group has prepared a document of about 150 pages which addresses the special fire safety considerations of very tall buildings.

At the time the project was conceived, there were several properties around the world that were being designed and constructed and that could be considered to be "very tall.” While the global economy has slowed that process somewhat, there will always be new projects being designed that are higher, and different than the codes envisaged when high-rise building requirements were written. Because each very tall building is unique, SFPE and ICC concluded that writing a "code” for very tall buildings was not the solution. Rather, writing a "Guide” for very tall buildings can provide designers, owners, authorities having jurisdiction, and the general public some information and advice on what should be considered when designing such buildings.

So what is a "very tall building?” The guide is intentionally vague on this point. The scope uses the following language:

The Guide pertains to all "super tall,” "very tall” and tall buildings. They are characterized by heights that impose fire protection challenges. They require special attention beyond the protection features typically provided by traditional fire protection methods. This guide does not establish a threshold of what constitutes a building that falls within its scope. It directs the user to perform a risk analysis to achieve a reasonable and adequate solution for the specific building.

The task group had a significant amount of discussion over the above language, and whether it provided enough guidance. The task group considered whether to use the term "high-rise” as defined in the model codes. Many codes begin to apply high-rise provisions at 3 to 7 stories, or about 17 – 20 meters. The task group concluded that the intent of the guide is for buildings much taller than these minimums, even though some of the same thought processes and design solutions may apply.

The building code provisions for high-rise buildings were typically written to address buildings with floors beyond the reach of external fire apparatus. A series of code provisions, which differ by code and country, have been written to respond to the need for internal rather than external approaches to fighting fire (and to some extent to rescuing people). Over the past few years, some additional thresholds have been added to some of the codes, requiring special features for taller buildings such as increased fire resistance, additional exit stairs, and special treatment of elevators, refuge floors or areas. These code provisions have often been added in a piecemeal basis without looking at how they may impact the building system as a whole.

The new SFPE guide will take a different approach. It recognizes that all of the features of the tall building must work together as a system. It also recognizes that, while codes must establish thresholds for requirements, they cannot be written to cover all eventualities, nor how the interaction of these features will add to or detract from the overall safety of the building. So, rather than establishing one set of criteria, the SFPE guide lays out the thought process that should be followed in determining the systems to be used and how they will interact.

The guide should cause any user to stop and think about their process or their approach. It discusses design approaches from around the world. Primarily, though, it discusses the items that any designer or owner should think about as they consider a very tall building. Using means of egress as an example, some of the questions it will pose will include:

• Should evacuation be partial, total or remain in place?
• If people are re-located, where should they go, e.g., ground floor, other floors, refuge floors, horizontal exits, or roof?
• Can or should elevators be a part of the exit scheme (serving that floor, serving sky-lobbies, serving refuge areas)?
• Will pressurization of stairs work? Do they need to be subdivided?
• How many separate routes are needed?
• What about alternate egress devices?

The guide has several sections, which can be used separately or together. All of them will contain information which will be of use to the user. As currently laid out, it is constituted as follows:

• Chapters 1 through 6 provide introductory material. This includes scope information, but also discusses several high-rise fires and lessons learned; some of the unique features of very tall building; and a long discussion on hazard risk and decision analysis in very tall buildings.
• Chapters 7 through 17 discuss systems in buildings. They include chapters on reliability and integration, and individual chapters on systems likely to be found in the building. Chapter 16 addresses first responder issues, which often do not get enough consideration early in the design process.
• Chapter 18 addresses building under construction. This is a particular challenge for very tall buildings.
• Chapters 19 to 21 address the on-going operations of the building. This includes life cycle management, commissioning, and inspection, maintenance and testing.
• Lastly, the appendix contains a long list of other places for information and recommended readings.

SFPE believes this guide will be a very useful reference document for designers, owners, authorities and other stakeholders. The task group expects it will be periodically updated to respond to changes in technology or to new lessons learned. Watch for the publication of the document early next year, and order it from SFPE or ICC.

James Quiter is with Arup

Related Articles:

2nd Quarter 2011 -- Evacuating High Rises: A strong international non-consensus -- Anthony Wood, Ph.D.
This editorial includes examples designed to show that the author feels there is far from any international consensus on evacuating high rises, including with regard to use of elevators for evacuation, introduction of a third fire stair, risks to buildings and cities, and use of sky bridges. While acknowledging that there are challenges in incorporating some strategies mentioned in this article, he looks towards a future where professionals work across disciplines to find solutions to these issues. READ MORE

Summer 2006 -- High-Rise Buildings: What Should We Do About Them? – James R. Quiter, P.E., FSFPE
The World Trade Center events of September 11, 2001, focused the world's attention on high-rise buildings. Since that time, there have been several other events that have kept the world's attention on high-rise building fire safety, including fires in Madrid, Venezuela, and two in Chicago. Major code groups in the United States and around the world have begun to seriously look at high-rise building safety and to question whether enough is being done. This article looks at some of the events that have occurred, evaluates lessons learned, discusses some of the recommendations currently being considered in high-rise safety design, and suggests ways forward to look at fire safety design and high-rise structures. READ MORE

Summer 2006 – Emerging Issues in High-Rise Building Egress – David A. de Vries, P.E., CSP
Traditional high-rise evacuation strategies that have been incorporated into model codes in the U.S. have been based on defend-in-place and/or partial evacuation and relocation. READ MORE