Masonry Magazine April 1997 Page. 11
The NBC publishes the National Building Code (NBC) and its area of influence span the northern states from the east coast to the Mississippi River. ICBO publishes the Uniform Building Code (UBC) and its general area of influence is from the west coast to the Mississippi River. SBCCI publishes the Standard Building Code (SBC) and its area of influence comprises the southern states from the Atlantic Ocean westward through Texas. See Figure A below.
The UBC has provisions for the strength design of masonry that are not found in the other two codes. Other differences exist and the masonry industry has adapted well to these various constraints. Overall, it is very important to note that the NBC and the SBC refer to consensus documents for design and materials standards, while the UBC maintains all these provisions in its three volumes.
The former method is considered by most to be better for the industry and it is the method adopted by the International Code Council. More on the consensus process and its relationship to the masonry industry later in this article.
Geographic Influence of Model Codes
Standard (SBCCI) Codes
Uniform (ICBO) Codes
National (BOCA) Codes
Two or More Model Codes
State Developed Codes
PREPARED BY THE COUNCIL OF AMERICAN BUILDING OFFICIALS
Figure A: The majority of states use either of the three model codes. Although states like Oklahoma have localities that use either the SBC or the BOCA NBC. Moreover, in Texas all three model codes can be found in use. The IBC will provide a nationwide code and proponents believe will be quickly adopted by all States and localties. Reproduced with permission from the Council of American Bulding Officials.
A few years back, an effort by the three code organizations coordinated the provisions of the three code documents into a common code format. As a result, code provisions can be found in the same chapter of each model code. In the NBC, SBC, and UBC masonry construction and design provisions are found in Chapter 21. However, specific provisions in the three building codes are different.
Residential construction is governed by the One and Two Family Dwelling Code (OTFDC), formerly referred to as the CABO code. It is a nationwide residential code that applies to construction, addition, alteration, repair, use, occupancy, and maintenance of detached one and two family dwellings and single family townhouses not more than three stories in height. The code is prescriptive in that all the necessary provisions, including design information, is incorporated into the code. Consequently, the code contains specified dimensions for building elements so that by using the values, a contractor is not required to have an engineered design. As noted later on, this code was adopted by the International Code Council.
Building Code Development Process
Building codes are dynamic instruments that are revised periodically to reflect advancements in construction practices. The model code change process provides an opportunity for innovations, new materials, new systems of construction, and new research to be brought into practical use. Participants in the code change process include industry associations, engineers, architects, as well as the state, county, and municipal code officials. This last group is very important, because the enforcers of the codes state, county, and municipal code officials control the content the code.
The three model codes consider code changes every year through a year long process call a code development cycle. For example, ICBO considered 314 code changes for the 1996 code development cycle. This process starts with the submission of written code change proposals accompanied by a reason statement and supporting evidence. Any individual or organization can submit a proposal. After submission, the changes are published for public review which leads to public hearings in front of code development committees. Typically, there are four to five standing committees that deal with certain aspects of the code. Members of these committees are building officials or regulatory personnel with the expertise in the area under consideration. Next, the proposals are published and the code development committees conduct the first of two public hearings to consider testimony on the proposed changes. Amendments are allowed at these hearings and, after floor debate and committee questions, the committee will vote on the change. The committee's recommendations are then published and distributed for review. This is followed by a challenge period, where anyone not agreeing with a particular committee recommendation can challenge the change at the organization's annual meeting. Finally, challenges are heard at the annual conferences and each challenge is subject to floor debate and a vote from the code body membership. At the end of the cycle, all approved changes are then included in a code supplement and every third year a new edition of the code is published. See figure B.
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