How to Approach This Alteration of Existing Building - First Post - Be Gentle! ;-)

[StLouis86]

So, I'm familiar with the IBC, though I've been doing residential work for some time and I'm a bit rusty. I have no experience with the International Existing Building Code, and I didn't consider that until just now, so if I should be using it, please advise. My question has to do with how to approach an alteration to an existing building, for which the AHJ is requesting an "overall building analysis to show that heights/areas and life safety codes are being met or maintained." The building is an existing , non-sprinklered, one-story, with basement:

1. Basement: 9,133 SF
2. First Level: 16,163 SF
3. Covered Storage attached to building: 7,010 SF

The existing building is a mix of B and S-1 uses, and for some reason was classified as non-separated, mixed-use when previously expanded in 2006, under the 1999 BOCA.

The local code is 2009 IBC.

We are essentially adding two exterior walls to enclose approximately 4,500 SF of the covered storage area (think carport) to create an S-1 garage space. See the attached plan (hopefully it will work!)
https://imgur.com/a/WIeC6K5

I first thought I should do non-separated and found that the more restrictive S-1 limit is 17,500 SF per floor. Since our entire footprint has >20' access, 1.5X area allowable gives me 17,500 x 1.5=26,250 SF. We will be under this amount.

Because we are trying to avoid adding sprinklers, I need to keep the S-1 Fire Areas under 5,000, which is easily accomplished since the existing exterior walls are 12" CMU. All we planned to do is replace existing doors with 3-hour doors, since the 12" CMU provides at least 3-hour separation.

Once I got to this point, I realized that this enclosed area can be considered a separate building, but I don't know how to complete the standard code analysis block that I am referring to in either of the two above scenarios. Or at least until I'm confident of the right way to approach this project, code-wise. I also keep coming back to the fact that we technically are not increasing the area of the building (since IBC considered the covered portion part of the building area).

The code "block" from the previous addition to this building, which I'm using for reference, includes:

• Codes
• Building Code Classification
• Use Group
• Construction Type
• Building Areas/Allowable Areas, including increases
• Occupant Loads
• Max. Travel Distance
• Exit Locations
• Dead End limits
• Storage Area separations
• Plumbing Fixture Counts (not on the referenced block, but in other examples)

I have not-to-scale PDFs of the existing building, that I can get close to scale, if I need to check existing widths, lengths, but I don't know that this is technically needed. Thanks in advance for helping educate me on this. If your reply is only to point out that I don't know what I'm doing, I assure you I've already figured that out.

 

[classicT]

I would recommend that you take a look at Statute 327.101(5) (below)

(5) Any person who renders architectural services in connection with the construction, remodeling or repairing of any privately owned building described in paragraphs (a), (b), (c), (d), and (e) which follow, and who indicates on any drawings, specifications, estimates, reports or other documents furnished in connection with such services that the person is not a licensed architect:

  (a) A dwelling house; or

  (b) A multiple family dwelling house, flat or apartment containing not more than two families; or

  (c) A commercial or industrial building or structure which provides for the employment, assembly, housing, sleeping or eating of not more than nine persons; or

  (d) Any one structure containing less than two thousand square feet, except as provided in (b) and (c) above, and which is not a part or a portion of a project which contains more than one structure; or

  (e) A building or structure used exclusively for farm purposes;

Looks like state laws require an architect.

 

[StLouis86]

Yep. Thanks. I obviously didn't take the time to explain every aspect of the project, the team, etc. The point is I'd like some advice on how someone with expertise would handle this. Hopefully somebody else will still offer their opinions on the questions I asked.

 

[classicT]

As you indicated in the OP, there are many methods which can be used to make this work. It will take someone intimately involved in the project to help you through the intricacies of each pathway. That person, would be an architect.

considered a separate building

Be careful with the idea of using firewalls to create separate buildings; firewalls require structural independence and openings (such as doors) would be prohibited within the firewall. If you can meet the provisions for mixed use and use fire barriers to reduce fire areas to point where fire sprinklers are not required, you have a path forward.

 

[Builder Bob]

Don't think your concept of plan will work........ Fire walls are a difficult thing to make into structural independence.

 

[StLouis86]

Yes, I feel confident that the original approach is the correct on to take. The idea of the fire walls and separate buildings had just been raised and I wasn't considering all the requirements to make that work. I appreciate the input. Thanks.

 

[BayPointArchitect]

Why are you limiting your fire areas to only 5,000 S.F. rather than 12,000 S.F.? Will there be commercial vehicles weighing more than 10,000 lbs each - parked inside and over night?

Is your building official wanting you to use the International Existing Building Code? I would think that Chapter 34 of the 2009 IBC would be the appropriate reference. It takes me four hours to evaluate the level of safety for any given building. So I think that you or an architect might need to sit down and score the building - if that is what your Building Official is asking for.

Otherwise, I am thinking that enclosing the dock area might have caused a legitimate exterior exit door to become a doorway into an intervening room. Your floor plan does not show enough context for me to know how existing warehouse areas are exiting without exceeding the common path of travel limit (either 50' per Life Safety Code, or 75' for nonsprinkled combustible storage, or 100' for nonsprinkled combustible storage with a calculated occupant load less than 30 people).

An overall floor plan would need to illustrate that dead ends are limited to something less than 20 feet in the business areas and 50 feet in the storage areas.

Maximum travel distance of 200' will not likely be an issue.

If I were your building official, I would simply require the building to be sprinkled and then let someone explain to me how the building is compartmentalized in order to reduce the fire areas to something less than 12,000 S.F. And I agree that a twelve inch thick CMU wall would be more than sufficient for fire separation.