• Introduction

    Internationally, code officials recognize the need for a modern, up-to-date residential code addressing the design and construction of one- and two-family dwellings and townhouses. The International Residential Code®, in this 2012 edition, is designed to meet these needs through model code regulations that safeguard the public health and safety in all communities, large and small.

    This comprehensive, stand-alone residential code establishes minimum regulations for one- and two-family dwellings and townhouses using prescriptive provisions. It is founded on broad-based principles that make possible the use of new materials and new building designs. This 2012 edition is fully compatible with all of the International Codes® (I-Codes®) published by the International Code Council® (ICC)®, including the International Building Code®, International Energy Conservation Code®, International Existing Building Code®, International Fire Code®, International Fuel Gas Code®, International Green Construction CodeTM (to be available March 2012), International Mechanical Code®, ICC Performance Code®, International Plumbing Code®, International Private Sewage Disposal Code®, International Property Maintenance Code®, International Swimming Pool and Spa CodeTM (to be available March 2012), International Wildland-Urban Interface Code® and International Zoning Code®.

    The International Residential Code provisions provide many benefits, among which is the model code development process that offers an international forum for residential construction professionals to discuss prescriptive code requirements. This forum provides an excellent arena to debate proposed revisions. This model code also encourages international consistency in the application of provisions.


    The first edition of the International Residential Code (2000) was the culmination of an effort initiated in 1996 by ICC and consisting of representatives from the three statutory members of the International Code Council at the time, including: Building Officials and Code Administrators International, Inc. (BOCA), International Conference of Building Officials (ICBO) and Southern Building Code Congress International (SBCCI), and representatives from the National Association of Home Builders (NAHB). The intent was to draft a stand-alone residential code consistent with and inclusive of the scope of the existing model codes. Technical content of the 1998 International One- and Two-Family Dwelling Code and the latest model codes promulgated by BOCA, ICBO, SBCCI and ICC was used as the basis for the development, followed by public hearings in 1998 and 1999 to consider proposed changes. This 2012 edition represents the code as originally issued, with changes reflected in the 2009 edition, and further changes developed through the ICC Code Development Process through 2010. Residential electrical provisions are based on the 2011 National Electrical Code® (NFPA 70). A new edition such as this is promulgated every three years.

    Energy provisions in Chapter 11 are duplicated from the International Energy Conservation Code®—Residential Provisions applicable to residential buildings which fall under the scope of this code.

    Fuel gas provisions have been included through an agreement with the American Gas Association (AGA). Electrical provisions have been included through an agreement with the National Fire Protection Association (NFPA).

    This code is founded on principles intended to establish provisions consistent with the scope of a residential code that adequately protects public health, safety and welfare; provisions that do not unnecessarily increase construction costs; provisions that do not restrict the use of new materials, products or methods of construction; and provisions that do not give preferential treatment to particular types or classes of materials, products or methods of construction.


    The International Residential Code is available for adoption and use by jurisdictions internationally. Its use within a governmental jurisdiction is intended to be accomplished through adoption by reference in accordance with proceedings establishing the jurisdiction's laws. At the time of adoption, jurisdictions should insert the appropriate information in provisions requiring specific local information, such as the name of the adopting jurisdiction. These locations are shown in bracketed words in small capital letters in the code and in the sample ordinance. The sample adoption ordinance on page xvii addresses several key elements of a code adoption ordinance, including the information required for insertion into the code text.


    The International Residential Code is kept up-to-date through the review of proposed changes submitted by code enforcing officials, industry representatives, design professionals and other interested parties. Proposed changes are carefully considered through an open code development process in which all interested and affected parties may participate.

    The contents of this work are subject to change both through the Code Development Cycles and the governmental body that enacts the code into law. For more information regarding the code development process, contact the Codes and Standards Development Department of the International Code Council.

    The maintenance process for the fuel gas provisions is based upon the process used to maintain the International Fuel Gas Code, in conjunction with the American Gas Association. The maintenance process for the electrical provisions is undertaken by the National Fire Protection Association.

    While the development procedure of the International Residential Code assures the highest degree of care, ICC, the founding members of ICC, its members and those participating in the development of this code do not accept any liability resulting from compliance or noncompliance with the provisions because ICC and its founding members do not have the power or authority to police or enforce compliance with the contents of this code. Only the governmental body that enacts the code into law has such authority.

    Code Development Committee Responsibilities

    In each code development cycle, proposed changes to the code are considered at the Code Development Hearings by the applicable International Code Development Committee as follows:

    [RB]=IRC—Building Code Development Committee
    [RE]=Residential Energy Code Development Committee
    [RMP]=IRC—Mechanical/Plumbing Code Development Committee

    The [RE] committee is also responsible for the IECC—Residential Provisions.

    Note that, for the development of the 2015 edition of the I-Codes, there will be two groups of code development committees and they will meet in separate years. The groupings are as follows:

    Group A Codes
    (Heard in 2012, Code Change Proposals Deadline: January 3, 2012)
    Group B Codes
    (Heard in 2013, Code Change Proposals
    Deadline: January 3, 2013)
    International Building CodeAdministrative Provisions (Chapter 1 all codes except the IECC, IRC and ICCPC, administrative updates to currently referenced standards, and designated definitions)
    International Fuel Gas CodeInternational Energy Conservation Code
    International Mechanical CodeInternational Existing Building Code
    International Plumbing CodeInternational Fire Code
    International Private Sewage
    Disposal Code
    International Green Construction Code
    ICC Performance Code
    International Property Maintenance Code
    International Residential Code
    International Swimming Pool and Spa Code
    International Wildland-Urban Interface Code
    International Zoning Code

    The International Residential Code is included in the Group B Codes. Therefore, any code change proposals to the IRC will be heard in the 2013 code cycle. The deadline for proposed changes to the IRC is January 3, 2013.

    Marginal Markings

    Solid vertical lines in the margins within the body of the code indicate a technical change from the requirements of the 2009 edition. Deletion indicators in the form of an arrow () are provided in the margin where an entire section, paragraph, exception or table has been deleted or an item in a list of items or a table has been deleted.

    A single asterisk [*] placed in the margin indicates that text or a table has been relocated within the code. A double asterisk [**] placed in the margin indicates that the text or table immediately following it has been relocated there from elsewhere in the code. The following table indicates such relocations in the 2012 Edition of the International Residential Code.

    R312.2 R612.2
    R507 R502.2.2
    R602.3.5 R602.
    R602.10.6.5 R602.12
    R702.7 R601.3

    Italicized Terms

    Selected terms set forth in Chapter 2, Definitions, are italicized where they appear in code text. Such terms are not italicized where the definition set forth in Chapter 2 does not impart the intended meaning in the use of the term. The terms selected have definitions which the user should read carefully to facilitate better understanding of the code.