Practice Exam Code Question
Hi All,
I am not understanding the following question from the PDD test practice question online. It seems this construction type (IV - heavy timber) does not allow a building this large using "S13R." We are also given no information on whether this if NFPA13 or NFPA13R and no information on area increases due to frontage in order to complete Equation 5-1 from the IBC. What am I missing? The explanation is short and not too helpful.
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NFPA 13R Sprinkler protection is only allowed for residential structures up to 4 stories. This question involves a 5-story residential building which requires using a NFPA13 system, therefore it would fall under the "SM" row allowing for 61,500sf per floor.
Always pay close attention to the number of floors when dealing with multi-family residential buildings & codes. Example being compliance with the Energy Code: Generally speaking, R-2 buildings that are 3-stories or less may be considered "residential" while R-2 buildings that are 4-stories or more are typically considered "commercial". There are more factors to take into account of course, but just keep in mind the # of floors may have specific requirements or restrictions. Another example relates to when elevators are required in R-2 buildings..
Hope that helps!
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Thank you to you both. One of you said S1 and the other SM. I believe it's SM, which is a value of 61,500 SF. However, looking at Equation 5-2 from IBC 506 (see below), the area of this "SM" building can be "61,500 SF X 3" MAX ignoring area increase due to frontage. This is less than 300,000 SF. What am I missing? You are only allowed to multiply the "61,500 SF" figure by a max of 3 in a multi-story building.
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You're right, this question is more confusing now that I'm looking at it closer..... Since it is sprinklered the allowable area would be multiplied by 4 not 3, but that only allows for a total building area of 246,000sf.... Unless they are considering this residential building to be multiple occupancies and not single occupancy??
Maybe someone at NCARB can weigh in on this and clarify, I'm stumped..
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Yeah, I really think it might be incorrect!
Since the provided information leads us to assume it's single-occupancy, we can therefore assume the calculation to calculate total building area is IBC 506.2.3 (Equation 5-2). We take the base area (61,500 SF for SM) and can multiple it by 3 max. We can't multiple it by four because you are only allowed to multiple by 4 when it's a NFPA 13R system.
Regardless of multiplying by three or four, we don't get to 300,000 SF.
NCARB, help! This makes me nervous for the actual exam.
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Thanks for the response! It's odd because in the ARE Handbook, there is a PDD sample code question about ramps that requires you to recall code knowledge. The code information is not provided.
So it seems like NCARB does require memorized code knowledge, like how to calculate building area.
The question also doesn't say that you can multiple the 61,500 figure by 5, so you do have to use code knowledge to understand you can multiply it by story count. Intrinsic in that knowledge is the knowledge the story count multiplier cannot exceed 3.
I'm stumped! I emailed NCARB so hopefully they will respond here for the group. :)
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Hello Rachel,
You are correct, items should not require memorization of the allowable area determination equation to answer accurately. It also requires an assumption be made that the building is able to take advantage of the max allowable area frontage increase which should have been stated. The calculation which makes IV correct is:
Allowable area = [61,500 + (20,500 x 0.75)] x 4 = 307,500 allowable area.
As you pointed out it is not possible to solve without memorizing that formula and then assuming the frontage increase is maximized. To fix those issues I've flagged it for our architect volunteer item writers to review and revise for a future release of the practice exam.
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@NCARB, thank you for the response, if this is an issue on a “practice” exam, what guarantee the candidates have that something similar wont appear on the actual exam. This too worries me that we dont have to memorize formulas but now it seems like that I may not be the case
Please advice
Thank you -
Hello Juan,
The volunteer architects who write items for the exam each year are required to provide reference formulas or exhibits for questions that would not be answerable without that formula or reference. Examples are things like lumen conversions, plumbing fixture calculations, or maximum building areas per code. We also provide a resources tab in all divisions of the exam that have common lighting, structural, acoustic, and other formulas to use as a reference.
To help make sure that missing formulas or code references like in the practice exam item here do not impact the actual exam we use a method called pretesting. On the real exam all new items are first pretested, where they look like all the other questions but do not actually impact the score of the candidate. We track how candidates answer those non-scored items and if it has an error or is not answerable, the statistics on that item will show that. We will then correct or remove the item before it can impact someone's score.
The difference with the practice exam however was that none of the items on it were pretested. We would not have been able to get reliable statistics on the quality of these items since the exam was open to the public and sharable. Instead we are relying on community members such as yourselves to catch any of the items that would have otherwise been flagged in the pretest phase on the real exam so that we can respond to them and correct them as needed.
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