Question of the Day - #61 We Clarified It!!!!

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Question of the Day - #61 We Clarified It!!!!

Postby RDavidson » Fri Nov 28, 2014 1:11 pm

You decide you are going to get your head around the requirements for residential sprinklers. You read the new definition for “floor area” that has been inserted in 2015 MR section 1309.0202 definitions. This definition says “floor area” is “the calculated square footage of the floor within the inside perimeter of the exterior walls of the building under consideration without deduction for hallways, stairways, closets, the thickness for interior walls, columns, or other features.” You want to understand why this new definition was put in the code and you go to the SONAR. The SONAR states that the purpose of the definition of “floor area” is to establish uniform applications as it applies to sprinkler requirements. The SONAR goes on to state that the definition of floor area is that area within the perimeter exterior walls. It makes sense that you have a definition for this contentious issue to eliminate any confusion.

Armed with the knowledge you just received from the SONAR you know that you can study this definition and know exactly how to apply the rules. Based on your experience in code enforcement you know that there is a definition for “exterior wall” in the Minnesota Residential Code. You look it up and it reads “An above-grade wall that defines the exterior boundaries of a building. Includes between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable end walls, walls enclosing mansard roof and basement walls with an average below grade wall area that is less than 50 percent of the total opaque and nonopaque area of that enclosing side.” So based on the last phrase in the definition you see that foundation walls enclosing a full depth basement aren’t, by definition, exterior walls so full depth basements won’t be included in the floor area. You believe that authors are smart because they used a defined term. Now you understand the intent and are ready to answer questions from the public regarding sprinkler requirements by telling them that full depth basements don’t contribute to floor area.

But your first question from the public isn’t about basements. They ask if the area of the garage is included. The wall between the dwelling and the garage is not by definition an exterior wall. You can only conclude given the definition that the garage is included. So you tell them for purposes of the definition, garages are included in the computation of floor area. Agree? Do you see any problems with the matter of uniformity?

But the caller says that additional commentary language regarding floor area has been inserted in R312 that excludes garages but includes all basements. The caller asks why they would have a definition intended to provide clarity and then need to clarify it but in another section? Do you tell the caller you don’t write the rules and go away?

Would it have been better to roll all of the text into one location in R312 that said something to the effect “for purposes of this section, floor area shall include all floors of the dwelling including basements but excluding garages…”?
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