Cover: Building Codes Illustrated, Seventh Edition by Francis D. K. Ching, Steven R. Winkel

Building Codes ILLUSTRATED

 

Seventh Edition

A Guide to Understanding the 2021 International Building Code®

 

 

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FRANCIS D. K. CHING / STEVEN R WINKEL, FAIA

 

 

 

 

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Disclaimer

The book contains the authors’ analyses and illustrations of the intent and potential interpretations of the 2021 International Building Code® (IBC). The illustrations and examples are general in nature and not intended to apply to any specific project without a detailed analysis of the unique nature of the project. As with any code document, the IBC is subject to interpretation by the Authorities Having Jurisdiction (AHJ) for their application to a specific project. Designers should consult the local building official early in project design if there are questions or concerns about the meaning or application of code sections in relation to specific design projects.

The interpretations and illustrations in the book are those of the authors. The authors do not represent that the illustrations, analyses, or interpretations in this book are definitive. They are not intended to take the place of detailed code analyses of a project, the exercise of professional judgment by the reader, or interpretive application of the code to any project by permitting authorities. While this publication is designed to provide accurate and authoritative information regarding the subject matter covered, it is sold with the understanding that neither the publisher nor the authors are engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought.

Acknowledgments

The authors and John Wiley & Sons would like to thank Jay Woodward, John “Buddy” Showalter, and Sandra Hyde of the International Code Council for their thorough review of the manuscript of the previous edition and for the review of this seventh edition. Their review does not reflect in any way the official position of the International Code Council. Any errors in the interpretations or illustrations in the book are solely those of the authors and are in no way the responsibility of the International Code Council.

We would also like to thank David Collins, FAIA, of The Preview Group, Inc., for his insightful review. The book was made clearer and our interpretations were improved by his comments and suggestions.

About the International Code Council®

The International Code Council is the leading global source of model codes and standards and building safety solutions that include product evaluation, accreditation, technology, codification, training, and certification. The Code Council's codes, standards, and solutions are used to ensure safe, affordable, and sustainable communities and buildings worldwide. The International Code Council family of solutions includes the ICC Evaluation Service, the International Accreditation Service, General Code, S. K. Ghosh Associates, NTA Inc., Progressive Engineering Inc., ICC Community Development Solutions, and the Alliance for National & Community Resilience. The Code Council is the largest international association of building safety professionals and is the trusted source of model codes and standards, establishing the baseline for building safety globally and creating a level playing field for designers, builders and manufacturers.

Washington DC Headquarters:

500 New Jersey Avenue, NW, 6th Floor, Washington, DC 20001

Distribution Center (Lenexa, KS)

888-ICC-SAFE (888-422-7233)

www.iccsafe.org

Family of Solutions:

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Preface

The primary purpose of this book is to familiarize code users with the 2021 International Building Codd® (IBC). It is intended as an instructional text on how the code was developed and how it is organized, as well as a primer on how to use the code. It is intended to be a companion to the IBC, not a substitute for it. This book must be read in concert with the IBC.

Many designers feel intimidated by building codes. They can seem daunting and complex at first glance. It is important to know that they are a product of years of accretion and evolution. Sections start simply and are modified, and new material is added to address additional concerns or to address interpretation issues from previous code editions. The complexity of a building code often comes from this layering of new information upon old without regard to overall continuity. It is important to keep in mind that there is no single author of the building code. Each section has a different author. Building codes are living documents, constantly under review and modification. It is vital to an understanding of codes to keep in mind that they are a human institution, written by ordinary people with specific issues in mind or specific agendas they wish to advance. It is also critical in code application to be sure you are using the most current code adopted in the jurisdiction where you are working.

Over the past several editions of the IBC there has been an increase in the number of code revisions made to “clarify” the code. This trend has often resulted in the reorganization of code sections, often without any substantive changes. For those code users who are familiar with the previous code editions these changes can be upsetting and confusing. It may seem that familiar and well-understood code provisions have disappeared when in actuality they have just been relocated and renumbered. We strongly recommend that code users obtain electronic copies of the codes. These lend themselves to keyword searches that make it possible to find moved provisions based on the unchanged text content. For identifying and understanding the major changes from one edition of the code to the next we suggest obtaining the Significant Changes to the IBC published by the International Code Council. Another valuable reference we recommend to accompany this book is the 2021 IBC Code and Commentary, also published by the International Code Council.

This book is designed to give an understanding of how the International Building Code is developed, how it is likely to be interpreted, and how it applies to design and construction. The intent of this book is to give a fundamental understanding of the relationship of codes to practice for design professionals, especially those licensed or desiring to become licensed as architects, engineers, or other registered design professionals. Code knowledge is among the fundamental reasons for licensing design professionals, for the protection of public health, safety, and welfare. It is our goal to make the acquisition and use of code knowledge easier and clearer for code users.

How and Why to Participate in the ICC Code Development Process

Architects, designers, engineers, and other professionals can freely participate in the ICC Code Development Process by submitting proposed code changes, collaborating with colleagues in developing code language and submitting changes, participating in giving testimony, and becoming ICC members to have voting opportunities in person or online at the Committee Action Hearings. The Code Development Process is conducted via ICC's state of the art cloud-based cdpACCESS system. Committee Action Hearings and Public Comment Hearings are broadcast live so anyone can follow the testimonies and actions taken. All building design and construction professionals are encouraged to participate in the ICC Code Development Process and have a say in the outcome of future International Building Codes or any other of the ICC International Codes. Because architects, engineers, and other design and construction professionals apply the code to actual buildings and experience first-hand the effectiveness of code provisions, it is very critical for them to participate in the code development process and improve the code each cycle. For the details of Code Development Process go to https://www.iccsafe.org/wp-content/uploads/ICC-CDP-How-It-Works.pdf. For information on cdpACCESS go to https://www.iccsafe.org/cdpaccess/.

How This Book Is Organized

The first two chapters of this book give background and context regarding the development, organization, and use of the IBC. Chapters 3 through 18 are organized and numbered the same as the corresponding subject-matter chapters in the IBC. Chapters 19-22 summarize the requirements in the remaining IBC chapters. Chapter 13 refers briefly to the energy provisions of the International Code family, which are contained in a separate code, the International Energy Conservation Code (IECC), and which are beyond the scope of this book. Chapter 23 touches on the code provisions for existing buildings, which are no longer included in the IBC, but occur in the International Existing Building Code (IEBC). While not addressed exhaustively in this book, new design work often takes place in existing buildings and we want to make code users aware of how the IBC and IEBC are to be applied in such cases.

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For the Student

The book is part of the introduction to building codes that are an integral part of professional studies in architecture, structural engineering, and civil engineering. It will serve as explanatory text to accompany analysis of the organization, intent, and use of codes in general and the International Building Code in particular. The introductory chapters will instill in undergraduate design students the reasons codes exist and how they form an integral part of the design process for every building project. Most design problems in school are at the schematic design level, so that detailed code analysis will not typically be undertaken in most undergraduate classes. In graduate classes the book can serve to organize and facilitate a deeper understanding of detailed requirements common to all building codes. The book also gives guidance on best practices for code analysis to lay a foundation for future practitioners to better meet the health, safety, and welfare criteria that are the basis for professional licensure.

For Emerging Professionals

Whether you are engaged in design, production, management, or construction administration, codes and standards are an integral and inescapable part of the practice of architecture and engineering. New practitioners need to refine their skills and knowledge of codes to make their projects safe and buildable with few costly changes. The more practitioners know about the code, the more it can become a tool for design rather than an impediment. The better the underlying criteria for code development and the reasons for code provisions are understood, the easier it is to create code-compliant designs. Early understanding and incorporation of code-compliant design provisions in a project reduces the necessity for costly and time-consuming rework or awkward rationalizations to justify dubious code decisions late in project documentation, or even during construction. Code use and understanding should be part of accepted knowledge for professionals, so that it becomes a part of the vocabulary of design.

For Experienced Practitioners

The greatest value of this book is that it is based on the widely adopted International Building Code. This code is similar but by no means identical to the three model codes—the Uniform Building Code, the National Building Code, and the Standard Building Code—that were used in the past. Various jurisdictions may be using differing editions of the IBC. Also, as noted, items have been moving around in recent editions of the IBC and this book can serve as a guide in keeping track of reorganized code sections. This book will guide experienced practitioners out of the old grooves of code use they may have fallen into with the old model codes, or with older editions of the IBC. The code-analysis methods and outcomes may vary from prior IBC editions to the new IBC. While there are seemingly familiar aspects from prior code editions interspersed throughout the new code, the actual allowable criteria and how they are determined are often quite different. It is likely that the illustrations and the underlying reasons for the development of each code section will look familiar to experienced practitioners. The experienced practitioner must not rely on memory or old habits of picking construction types or assemblies based on prior practice. Each building must be looked at anew until the similarities and sometimes-critical differences between the new code and old habits are understood and acknowledged. This admonition also applies to the need to determine local modifications to codes and not assume new projects in new locations are identical to similar prior projects.

How to Use This Book

This book focuses on the use and interpretation of the nonstructural provisions of the International Building Code. There are references to basic structural requirements, but this book does not attempt to go into structural requirements in depth. That is the subject for another volume.

The organization of this book presumes that the reader has a copy of the latest version of the IBC itself as a companion document. The book is intended to expand on, interpret, and illustrate various provisions of the code. The IBC has been adopted in many jurisdictions. As it has now been extensively | applied, there is an evolving body of precedent in application and interpretation. It is our hope that the analysis and illustrations in the book will aid the designer and the Authorities Having Jurisdiction (AHJ) in clarifying their own interpretations of the application of code sections to projects.

The book is not intended to take the place of the 2021 International Building Code® (IBC) in any way. The many detailed tables and criteria contained in the IBC are partially restated in the book for illustrative purposes only. For example, we show how various tables are meant to be used and how we presume certain parts will be interpreted. When performing a code analysis for a specific project, we anticipate the reader will use our book to understand the intent of the applicable code section and then use the code itself to find the detailed criteria to apply. One can, however, start with either the IBC or this book in researching a specific topic.

Beginning with the 2021 International Building Code®:

  • Search Contents or Index.
  • Read relevant section(s).
  • For further explanation and/or clarification, refer to this book.

Beginning with Building Codes ILLUSTRATED:

  • Search Code Index for section number or Subject Index for topic.
  • Refer back to specific text of 2021 International Building Code®.

The text is based on the language of the code and interprets it to enhance the understanding of the user. The interpretations are those of the authors and may not correspond to those rendered by the AHJ or by the International Code Council (ICC). This book, while based on a publication of the ICC, does not in any way represent official policies, interpretations, or positions of the ICC. We would encourage the users of the book to confer with the AHJ, using the illustrations from this book to validate interpretations. Reconciling text with construction drawings often benefits from additional illustrations. We trust that this will be the case with the explanations and graphics in this book.

Note that the text of the 2021 IBC contains terms in italic type. These italicized terms appear in the definitions in Chapter 2 of the IBC. Where defined terms are used in ways intended by their definitions, they are italicized in the body of the IBC. Italicized type is not used in this book in the same way. The IBC publisher's intent for this notification method is to highlight for the code user that the definitions should be read carefully to facilitate a better understanding of how they are used in the context where they appear in italics. It is critical that the code user go back to the IBC's definitions when attempting to understand the literal and figurative meaning of code requirements. All code definitions are now located in Chapter 2 of the IBC.

The primary purpose of the International Building Code (IBC) is to provide reasonable safeguards for the design, construction, use, occupancy, and maintenance of buildings. Participation by numerous volunteers representing all segments of the building community continue to log countless hours to ensure the code is updated every three years and reflects the current state of the art advances in building safety, resiliency, and performance. Developed through an open and transparent process, the IBC provides a balanced approach to safety, affordability, sustainability, and resiliency of buildings.

To the uninformed, building codes can appear limiting or even serve as a roadblock to building design and construction. Building codes have also been accused of being too rigid or static and unable to stay abreast of innovation or the latest advances in technology. While no one denies the need for a building regulatory system to address the safety and welfare of the public, everyone wants it to be effective, flexible, and allow for innovation. To the informed user of the IBC, the opportunity has always existed for designers, builders, manufacturers, and code officials to apply the performance-based provisions of the code in a manner that allows for creativity, flexibility, and affordability in building construction. The current 2021 International Building Code states the following:

“The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material and method of work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety.”

With advances in technology, competition, and the globalization of our economy, it is critical that building codes be dynamic and provide a pathway for the approval of new and innovative materials, designs, and methods of construction. Often, Code officials utilize research reports, listings, and/or test reports from approved sources providing verification of code compliance. The independent source that code officials frequently use to verify that a product is certified to a standard within the code, or an innovative or new product is evaluated to criteria that meet the building code requirements in terms of strength, effectiveness, fire resistance, durability, and safety, is the ICC Evaluation Service, Inc. (ICC-ES). Functioning as a subsidiary of the International Code Council, ICC-ES works closely with manufacturers, code officials, and the design community in an effort to facilitate the acceptance of products in the marketplace without compromising public safety. Information on products that have been reviewed by ICC-ES for code compliance can be downloaded at no cost by visiting http://www.icc-es.org/Evaluation_Reports/ or http://www.icc-es.org/.

The seventh edition of Building Codes Illustrated builds on the successful foundation laid by previous editions. Codes by their very nature tend to be tedious, dry documents that can also serve the late-night insomniac in search of relief. Building Codes Illustrated brings the code to life through its use of numerous illustrations accompanied with clear, concise, easy-to-understand text that spares the reader the normal legalese contained in regulatory documents. This updated guide continues its long tradition of serving as a key resource for those interested in not only understanding the code, but applying it as well.

Mark A. Johnson

Executive Vice President and Director of Business Development

International Code Council, Inc.

Metric Equivalencies

The 2021 International Building Code® uses the following SI units.

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