1、 2015CODE AND COMMENTARYThe complete IRC with commentary after each sectionVOLUME 1IRC2015 International Residential Code CommentaryVolume 1First Printing: August 2015ISBN: 978-1-60983-284-1 (soft-cover edition)COPYRIGHT 2015byINTERNATIONAL CODE COUNCIL, INC.ALL RIGHTS RESERVED. This 2015 Internatio
2、nal Residential CodeCommentaryVolume I is a copyrighted work ownedby the International Code Council, Inc. Without advance written permission from the copyright owner, no part of this book maybe reproduced, distributed or transmitted in any form or by any means, including, without limitation, electro
3、nic, optical ormechanical means (by way of example, and not limitation, photocopying, or recording by or in an information storage retrievalsystem). For information on permission to copy material exceeding fair use, please contact: Publications, 4051 Flossmoor Road,Country Club Hills, IL 60478. Phon
4、e 1-888-ICC-SAFE (422-7233).Trademarks: “International Code Council,” the “International Code Council” logo and the “International Residential Code” aretrademarks of the International Code Council, Inc. PRINTED IN THE U.S.A.2015 INTERNATIONAL RESIDENTIAL CODECOMMENTARY iiiPREFACEThe principal purpos
5、e of the Commentary is to provide a basic volume of knowledge and facts relating to building constructionas it pertains to the regulations set forth in the 2015 International Residential Code. The person who is serious about effectivelydesigning, constructing and regulating buildings and structures
6、will find the Commentary to be a reliable data source and refer-ence to almost all components of the built environment.As a follow-up to the International Residential Code, we offer a companion document, the International Residential CodeCommentaryVolume I. Volume I covers Chapters 1 through 11 of t
7、he 2015 International Residential Code. The basic appealof the Commentary is thus: it provides, in a small package and at reasonable cost, thorough coverage of many issues likely to bedealt with when using the International Residential Code and then supplements that coverage with historical and tech
8、nicalbackground. Reference lists, information sources and bibliographies are also included.Throughout all of this, effort has been made to keep the vast quantity of material accessible and its method of presentationuseful. With a comprehensive yet concise summary of each section, the Commentary prov
9、ides a convenient reference for regula-tions applicable to the construction of buildings and structures. In the chapters that follow, discussions focus on the full meaningand implications of the code text. Guidelines suggest the most effective method of application, and the consequences of notadheri
10、ng to the code text. Illustrations are provided to aid understanding; they do not necessarily illustrate the only methods ofachieving code compliance.The format of the Commentary includes the full text of each section, table and figure in the code, followed immediately by thecommentary applicable to
11、 that text. At the time of printing, the Commentary reflects the most up-to-date text of the 2015 Inter-national Residential Code. Each sections narrative includes a statement of its objective and intent, and usually includes a discus-sion about why the requirement commands the conditions set forth.
12、 Code text and commentary text are easily distinguished fromeach other. All code text is shown as it appears in the International Residential Code, and all commentary is indented below thecode text and begins with the symbol . All code figures and tables are reproduced as they appear in the IRC. Com
13、mentary fig-ures and tables are identified in the text by the word “Commentary” (as in “see Commentary Figure 704.3”), and each has a fullborder.Readers should note that the Commentary is to be used in conjunction with the International Residential Code and not as asubstitute for the code. The Comme
14、ntary is advisory only; the code official alone possesses the authority and responsibility forinterpreting the code.Comments and recommendations are encouraged, for through your input, we can improve future editions. Please direct yourcomments to the Codes and Standards Development Department at the
15、 Central Regional Office.iv 2015 INTERNATIONAL RESIDENTIAL CODECOMMENTARY 2015 INTERNATIONAL RESIDENTIAL CODECOMMENTARY vTABLE OF CONTENTSPart IAdministrativeCHAPTER 1 SCOPE AND ADMINISTRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1-26Par
16、t IIDefinitionsCHAPTER 2 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2-50Part IIIBuilding Planning and ConstructionCHAPTER 3 BUILDING PLANNING . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3-146CHAPTER 4 FOUNDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4-68CHAPTER 5 FLOORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5-58CHAPTER 6 WALL CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6-256CHAPTER 7 WALL COVERING. . . . . . . . . . . . . . . . . . . . . . .
19、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7-44CHAPTER 8 ROOF-CEILING CONSTRUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1 8-62CHAPTER 9 ROOF ASSEMBLIES . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 9-40CHAPTER 10 CHIMNEYS AND FIREPLACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1 10-22Part IVEnergy ConservationCHAPTER 11 ENERGY EFFICIENCY . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1 11-84INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-1 INDEX-14vi 2015 INTERNATIONAL RESIDENTIAL CODEC
22、OMMENTARY 2015 INTERNATIONAL RESIDENTIAL CODECOMMENTARY 1-1Part IAdministrativeChapter 1:Scope and AdministrationGeneral CommentsThis chapter contains provisions for the application,enforcement and administration of requirements of thecode. In addition to establishing the scope of the code,Chapter 1
23、 identifies which buildings and structurescome under its purview. Chapter 1 is subdivided into two parts. Part 1 includesscope and application, Sections R101 and R102. Part 2covers administration and enforcement, Sections R103through R114. Section R101 addresses the scope of the IRC. Section R102 es
24、tablishes the applicability of thecode and addresses existing structures. Section R103 establishes the department of build-ing safety and the appointment of department per-sonnel. Section R104 outlines the duties and authority ofthe building official with regard to permits, inspec-tions and right of
25、 entry. It also establishes theauthority of the building official to approve alterna-tive materials, used materials and modifications. Section R105 states when permits are requiredand establishes procedures for the review of appli-cations and the issuance of permits. Section R106 describes the infor
26、mation that mustbe included on construction documents submittedwith the application. Section R107 authorizes the building official toissue permits for temporary structures and uses. Section R108 establishes requirements for a feeschedule. Section R109 includes inspection duties of thebuilding offici
27、al or an inspection agency that hasbeen approved by the building official. Section 110 details provisions for the issuance ofcertificates of occupancy. Section R111 gives the building official the author-ity to approve utility connections. Section R112 establishes the board of appealsand the criteri
28、a for making applications for appeal. Section R113 addresses administrative provisionsfor violations, including provisions for unlawfulacts, violation notices, prosecution and penalties. Section R114 describes procedures for stop workorders. Each states building code enabling legislation, whichis gr
29、ounded within the police power of the state, is thesource of all authority to enact building codes. Policepower is the power of the state to legislate for the gen-eral welfare of its citizens. This power enables passageof such laws as building codes. If the state legislaturehas limited this power in
30、 any way, the municipality maynot exceed these limitations. While the municipality maynot further delegate its police power (e.g., by delegatingthe burden of determining code compliance to the build-ing owner, contractor or architect), it may turn over theadministration of the building code to a mun
31、icipal offi-cial, such as a building official, provided that sufficientcriteria are given to establish clearly the basis for deci-sions as to whether a proposed building conforms to thecode.Chapter 1 is largely concerned with maintaining “dueprocess of law” in enforcing the building performancecrite
32、ria contained in the body of the code. Only throughcareful observation of the administrative provisions canthe building official reasonably hope to demonstrate that“equal protection under the law” has been provided.While it is generally assumed that the administrationand enforcement section of a cod
33、e is geared toward abuilding official, this is not entirely true. The provisionsalso establish the rights and privileges of the design pro-fessional, contractor and building owner. The position ofthe building official is merely to review the proposed andcompleted work and to determine if the constru
34、ctionconforms to the code requirements. The design profes-sional is responsible for the design of a safe structure.The contractor is responsible for constructing the struc-ture in compliance with the plans.During the course of construction, the building officialreviews the activity to ascertain that
35、 the spirit and intentof the law are being met and that the safety, health andwelfare of the public will be protected. As a public ser-vant, the building official enforces the code in an unbi-ased, proper manner. Every individual is guaranteedequal enforcement of the provisions of the code. Fur-ther
36、more, design professionals, contractors and buildingowners have the right of due process for any require-ment in the code.SCOPE AND ADMINISTRATION1-2 2015 INTERNATIONAL RESIDENTIAL CODECOMMENTARYPART 1SCOPE AND APPLICATIONSECTION R101GENERALR101.1 Title. These provisions shall be known as the Resi-d
37、ential Code for One- and Two-family Dwellings of NAMEOF JURISDICTION, and shall be cited as such and will bereferred to herein as “this code.” The code is formally known as the International Resi-dential Code(IRC) for One- and Two-family Dwell-ings, generally referred to as the InternationalResident
38、ial Code or IRC for short. On adoption by thejurisdiction, it is known as the Residential Code forOne- and Two-family Dwellings of the adopting juris-diction, and in the document is often referred to as “thecode.” It is offered for adoption as a model document ofprescriptive provisions to jurisdicti
39、ons as a stand-aloneresidential code that establishes minimum regulationsfor one- and two-family dwellings and townhouses.The forum under which the code is developed encour-ages consistency of application of its provisions, and itis offered ready for adoption by all communities, largeand small, inte
40、rnationally.The purpose of this section is to identify the adoptedregulations by inserting the name of the adopting juris-diction into the code.R101.2 Scope. The provisions of the International Residen-tial Code for One- and Two-family Dwellings shall apply tothe construction, alteration, movement,
41、enlargement,replacement, repair, equipment, use and occupancy, location,removal and demolition of detached one- and two-familydwellings and townhouses not more than three stories abovegrade plane in height with a separate means of egress andtheir accessory structures not more than three stories abov
42、egrade plane in height.Exceptions:1. Live/work units located in townhouses and comply-ing with the requirements of Section 419 of theInternational Building Code shall be permitted to beconstructed in accordance with the InternationalResidential Code for One- and Two-Family Dwell-ings. Fire suppressi
43、on required by Section 419.5 ofthe International Building Code where constructedunder the International Residential Code for One-and Two-family Dwellings shall conform to SectionP2904.2. Owner-occupied lodging houses with five or fewerguestrooms shall be permitted to be constructed inaccordance with
44、 the International Residential Codefor One- and Two-family Dwellings where equippedwith a fire sprinkler system in accordance with Sec-tion P2904. The provisions of the code apply to all aspects of con-struction for detached one- and two-family dwellings;multiple single-family dwellings, defined as
45、town-houses; and all structures accessory to the dwellingsand townhouses. This section sets a limitation in itsscope of application to include only those townhouses,one- and two-family dwellings, as well as the acces-sory structures to such townhouses and dwellings, thatare up to and including three
46、 stories above grade andwhere a separate means of egress system is providedfor each of the dwelling units. The definition of town-house covered in the code must meet four criteria: 1. Itis not more than three stories in height; 2. It has a sep-arate means of egress; 3. Each unit extends from foun-da
47、tion to roof; and 4. There is open space on at leasttwo sides. Where a dwelling or townhouse exceeds theallowed height in stories, does not provide individualegress for each dwelling unit or does not conform tothe prescriptive provisions of the code, the structuresare then beyond the scope of the co
48、de and the provi-sions of the code cannot be applied. The building mustthen meet the provisions of the International BuildingCode(IBC) or other legally adopted building code ofthe jurisdiction. The actual height of the building, mea-sured in feet and applied to the height of each story, islimited by the governing provisions for each specificmaterial as found in Chapter 6 of the code. The user ofthe code will discover that, depending on which mate-rial is selected for the wall construction, the result maybe buildings of different permitted heights. ForPurposeA building code, as with
