QUESTION: This is a 11,000 s.f. metal building in Florida, that initially was a warehouse. The owner divided the building in 2. one half is now a mercantile occupancy and the other half is a church (assembly A3, The current tenant separation is a 2 hr. rated. Now the fire inspector says that the building needs sprinkler system. Is this true? Is there a way to get around this? What happen if I increase the tenant separation rating? so each half of the building will independent.

ANSWER: I assume that this is a one story building, Type IIB construction which is the same as Type II(000) construction.  Every part of the interior walls and roof is non-combustible.
You explained that this is a metal building.  Is there any wood framing for the interior walls?
Are there any stairs anywhere in the building?

Regardless of the variables mentioned above, if the Fire Inspector has determined that the calculated occupant load is greater than 300 people, then NFPA 101 Life Safety, Section will trigger the automatic sprinkler system.  If this is the case, your only hope for arguing an occupant load less than 300 people is to show how you fill up the church seating area (less than 4,500 S.F.) with tables and chairs.  The IBC Building Code will have the same requirement in accordance with Section 903.2.1.3 unless you can provide reasonable argument that we are dealing with less than a maximum occupant load less than 300 people.  No other way out of it.

Good luck.

Richard Burton, AIA
Registered Architect
(but not registered in Florida)
ICC Certified Plan Reviewer
NFPA Certified Fire Plan Examiner

---------- FOLLOW-UP ----------

QUESTION: Thanks for your quick answer. The construction type is IIB, one story, all the interior partitions are metal studs, and there is no stairs. The inspector stated that due to the size of the building it needs sprinklers.
I could reduce the number of persons on the assembly side, so it is less that 300, but what happen with the mercantile occupancy? What is the maximum occupant load that I need to get in the whole building (for both occupancies) so I do not have to install sprinklers?
What if I increase the fire rated separation to 3 or 4 hr?

Before I answer this question, I must explain that I am using the IBC references which are generally consistent with the NFPA Life Safety requirements.  Just be certain that while having a discussion with the Fire Investigator that you try to speak his language.  Sometimes fire investigators get a little cross when making reference to a slightly different code.
Say, "NFPA Life Safety 101".  That is very good.

First let us look at Table 508.4 where the required separation between the A3 occupancy (Church) and the M occupancy (Retail) is 2 hours.
Nothing more and nothing less for a building that is non-sprinkled.

Next let us look at the sprinkler requirements for the Mercantile/Retail space.
Less than 12,000 S.F. = no need to sprinkle.
Located on grade plane = no need to sprinkle.
Is it clear that this area is NOT for the display and sale of upholstered furniture or mattresses exceeding 5,000 square feet?
If so, then it will need to be sprinkled.

Finally let us look at the sprinkler requirements for the church area.
It is clear that the space needs to be sprinkled if the fire area is more than 12,000 S.F.
It is not.
It is clear that the space needs to be sprinkled if the fire area is located on a floor other than the exit discharge.
It is not.
It is clear that the space needs to be sprinkled if the occupant load is more than 300 people.
What is the calculated occupant load?

The answer to your question will be determined by the calculated occupant load for the church.

A three-hour fire-rated wall between the A3 and M occupancy will not provide the answer.
A four-hour fire-rated wall between the A3 and M occupancy will not provide the answer.

The answer to your question will be determined by the calculated occupant load for the church.


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Richard Burton AIA


A combined total of 25 years experience with construction, architecture, and building code enforcement. Ask me about residential and commercial design. Ask me about design aesthetics, structural methods, and building something that will withstand severe weather conditions. Ask me my opinion about YOUR design ideas and I will tell you the merits of good design and challenge your thinking about practical issues. Ask me how to best find and work with your local architect and approach general contractors to get the most value for the least amount of headaches. You can ask me about improving your energy efficiency and things that are both green and practical. But don't ask me about solar panels and wind turbines unless you are currently paying your utility company 35 cents per Kilowatt. Otherwise the math does not justify the initial cost and return on investment. Ask me any building code question and how to get a building permit from the most difficult enforcement agencies.


Here in the midwest, we design and build "green" in ways that make sense. My construction methods prioritize weather resistance, ease of maintenance and durability. While a graduate student in San Diego, I taught drafting and history of architecture. After working ten years for other architecture firms, I have started my firm Arrow Architecture in 2008. More than half of my work involves commercial office buildings. But my portfolio of work also includes custom homes, residential additions, home remodels, and second story additions.

President-Elect of American Institute of Architects - Lincoln, NE

B.S. Architecture - (Interior Design) University of Nebraska Lincoln 1997 Master of Architecture - (Urban Design and Professional Practice) NewSchool of Architecture - San Diego 2004 Graduated Summa Cum Laude ICC Certified Building Plans Examiner

Awards and Honors
AIA Henry Adams Medal and Certificate

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