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Have a Code Question? Take Advantage of the “Significant Changes”

International Residential Codes can change every three years and it’s a chore to keep up with the changes. It’s not uncommon to have questions on the meanings of new codes, and the IRC Commentary is the first place industry professionals turn when looking for answers and clarifications. However, when the Code Commentary does not fully address the questions being raised, what other resources do we have to find answers? We can easily search the web, but how do we know if what we find is a trusted source? One resource we often forget is to simply review the Significant Changes Book from the year the code was added.

Here’s an example:

A Builder reads section P2705.1 #5 of the 2015 IRC which states,

“Water closets, lavatories, and bidets. A water closet, lavatory or bidet shall not be set closer than 15 inches (381 mm) from its center to any side wall, partition or vanity or closer than 30 inches (762 mm) center-to-center between adjacent fixtures. There shall be a clearance of not less than 21 inches (533 mm) in front of a water closet, lavatory or bidet to any wall, fixture or door.”

The Builder then intuitively translates the words into everyday language and reads “water closets, lavatories and bidets” as “sinks, commodes and bidets“. But does that translation hold up?

When walking one of his homes he notices a marble top vanity sink center 14 inches from a side wall and remembers P2705.1 but isn’t sure it applies here. He’s been building the same way and installing the same sink for years and doesn’t recall there ever being a problem.

He goes back to verify the IRC language and digs in further with the Code Commentary. The Code Commentary tells him that “plumbing fixtures require space around them for use and cleaning purposes”, so he’s left wondering if this would negate the 15”-to-centerline requirement since this is a marble top vanity sink. Still unsure, he decides to reach out to his third-party inspection company for answers.

The inspection company points to the Significant Changes Book from the year the code was implemented – which in this case was two code cycles ago in 2009. After clearing the dust off the old 2009 book, the Builder goes on to see that this particular code only applies to wall-hung and pedestal lavatories, not sinks in or on vanity cabinets. So, as the Builder had hoped all along, there was no code violation and the home could stay on track to close.

In this situation, how would the Builder have known about this change unless he went back to read the 2009 Significant Changes? He could have guessed at what the commentary for the code meant or hoped the web results he found were accurate, but the only way to know for sure was to look back at the Significant Changes to the 2009 Code.

When you find yourself stuck with a code question, be sure and use all of your available resources including the Significant Changes to the original code. Often, the answer is just a few flips of the page away, even if you have to dust off an old code book. And when in doubt, ask an expert. There’s no need to struggle with a code question when a code expert is just a phone call away. Your third-party inspection company should be there to answer any of your code questions when they arise.


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