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Understanding Undefined Terms in the Building Codes

In building codes, not every term or phrase is explicitly defined. The provision addressing undefined terms ensures clarity and uniformity in interpreting the code. It states:

"Where terms are not defined through the methods authorized by this chapter, such terms shall have ordinarily accepted meanings such as the context implies."

This guidance highlights a hierarchical approach to understanding terms:
  1. Ordinarily Accepted Meanings:
    • If a term is not explicitly defined within the International Codes (I-Codes®), it should be interpreted based on its commonly accepted meaning. A standard dictionary definition often suffices, provided it aligns with the term’s context in the code.
  2. Context Matters:
    • The meaning of a term should be inferred based on the specific context in which it appears. This prevents misinterpretation and ensures that the intent of the code is upheld.
  3. Specialized Terms:
    • Some construction terms used in the code may not appear in standard dictionaries. In such cases, it is appropriate to refer to:
      • Referenced Standards: Chapter 16 of the code includes referenced standards that may define terms used in specialized contexts.
      • Published Textbooks: Technical books and industry-specific publications often provide detailed definitions and explanations for construction-related terms.
This approach ensures that the code remains adaptable and practical, enabling users to interpret terms accurately, even when definitions are not explicitly provided. By relying on context, referenced standards, and reputable resources, professionals can maintain the integrity and intent of the building code in their applications.

Understanding how to handle undefined terms is essential for ensuring compliance and consistency in the building industry. This provision empowers code users to make informed interpretations while adhering to the code’s purpose and intent.
 
Only related to definitions and code, I met recently with a code consultante who worked nationally. He opined that in he west enforcerd seemed to focus on definitions first and then code; while in east they only focused on definitions after they code. In my nearly 50 years active in code development I concur. ICBO folks seem to want to write every definition first, and then develop the code. BOCA folks focused on the code text and only reluctantly wrote a definition. This seemed more efficient and clearer especially for a term used only one or a few times.
 
BOCA folks focused on the code text and only reluctantly wrote a definition. This seemed more efficient and clearer especially for a term used only one or a few times.
The problem with this view is you need to define terms to make sure your talking about the same thing.
A perfect example is the term "plenum". Plenum in the IMC and commercial HVAC use has a vastly different meaning than it does when used by a residential HVAC tech.

IMC definition/Commercial: An enclosed portion of the building structure, other than occupiable space being conditioned, that is designed to allow air movement, and thereby serve as part of an air distribution system. Wild return above a lay in ceiling is a typical example.
Common residential HVAC use: A box or chamber that connects the air handling unit (AHU) to the ductwork in an HVAC system. Typically a sheen metal box that sits on top of the furnace or air handler as basically the beginning of the duct system.

When I tell a residential installer doing their first commercial job they have problems in their plenum they have no idea what I'm talking about until I explain it to them. This is a discrepancy within a trade.
 
I can't recall an instance where there was confusion about the meaning of a single word. There have been plenty of times that the interpretation of a string of words resulted in either a violation or a strange result. Foe example, If I write the correction, "Install a second ground rod a minimum 6'away from the first rod." I get this:

IMG_8406.JPG

After the second time that it happened I replaced ' with the word feet. Oddly enough, it still happened.

Another poorly worded violation is: "No kitchen counter space shall be more than 24" away from a receptacle." This results in receptacles spaced 24" apart.

Something else to consider is that Spanish is sorta backwards. Where we would say, "hot water" the Mexican population would say, "water hot". For us it's a water heater... for them it is a boiler agua.
 
It was an observation, not an opinion. Don't use the word plenum in your example. Use the words that you would use to define plenum.

My example is platform in section 410. Now platform is used many places in the code with nothing to do with the defined platform. If I 410 instead of saying platform, you say raised floor area, problem and confusion go away, and you don't have to look up a word.

If you use a word a lot, in many places in the code, and it doesn't have a usual and customary meaning, sure, define it. But then don't use that word differently in other parts of the code. And if it's only used once, just use the definition where it's used.

NFPA maintains a glossary of all defined terms which makes it easier to not create the kind of confusing code you point to. Not perfect but an attempt for clarity.

My views based on nearly 38 years active in code and standards development and I'm sure thousands of hours in committee meeting reviewing proposals and trying to write clear code. I've always subscribed to the first goal of code writing is that most people read it the same way.
 
If you use a word a lot, in many places in the code, and it doesn't have a usual and customary meaning, sure, define it. But then don't use that word differently in other parts of the code.
Plenum is used consistently in the code, and more than once. Its not used consistently in common practice. IMC section 602 is an entire 2 page section dealing with nothing but plenums. That's precisely why it needs to be defined, so everyone's on the same page. I was just using this as an example I deal with every day.
 
Plenum is used consistently in the code, and more than once. Its not used consistently in common practice. IMC section 602 is an entire 2 page section dealing with nothing but plenums. That's precisely why it needs to be defined, so everyone's on the same page. I was just using this as an example I deal with every day.

If the term is used a lot and is not obvious, sure, have a codecdefinition. Then maybe work towards two terms and two definitions since it seems to mean different things. Perhaps "plenum" and "residential plenum". I'd certainly compile a list of definitions from codes and standards as a starting point, and then prepare code change proposals.

(I'm guessing this is one an uninhabited space that is part of the air distribution system and two the return air chamber or box on the side or top of a typical residential furnace, but no expert so dont really know. My experience is with under floor plenums and supplying air by disfussion through openings in the floor.)
 
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