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Unlimited Area Building - 3 Story ??

H

Hyrax4978

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Joined
Nov 28, 2016
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242
Location
Hartford, CT
Looking to do an addition for a client.

The last addition they did was a three story B use structure, it was separated by a fire wall from an existing 2 story unlimited area building. Building is fully sprinklered.
Two additions ago, the code summary said unlimited area building. but the last addition they built ignored that, put on a fire wall, and did a three story addition.

I don't see any place where there can be a three story B use as part of an unlimited are building. Or am i missing something.

My other question would be.... could they have legally added onto an unlimited area building with a fire wall separation. doesn't a fire wall omit the open perimeter requirement of the UAB?

Thank you,
 
No and yes.....The 94 BOCA I believe had a little more flexibility on the open perimeter. How long ago was the last addition? Bad designer and/ or building department that doesn't know their history very well.....
 
The last addition was put on less than two years ago. put on by someone who is known for cutting corners. So im trying to figure out how to do an addition for the client and be code compliant. Im stuck at this point.
I don't see how you can have an unlimited area building if you have a separate 3 story building attached and separated by a fire wall.
 
I think this was when you only needed 75% open...

STATE BUILDING CODE INTERPRETATION NO. I-40-99 August 25, 1999 The following is offered in response to your request for interpretation of Section 507.2 of the 1999 State Building Code. Your questions seek clarification of the circumstances under which a building or buildings of limited area may be adjacent to, and on the same lot as, a building of unlimited area. Question 1: May several buildings be adjacent to the unlimited area building, provided the total length of all fire walls does not exceed 25 percent of the total perimeter of the unlimited area building, and all other criteria of the exception are met? Answer 1: No. The code is specific in the exception to Section 507.2 in the use of the singular in the phrase “facing another building on the same lot”. The code relies on the provisions of Section 503 to limit the area of buildings which do not qualify as unlimited area buildings based on Use Group and Construction Classification. These provisions provide an inherent check on the area of a building which can be constructed adjacent to an unlimited area building. To allow more than one building to be adjacent to the unlimited area building would remove the protection afforded by Section 503 and could result in the adjacent buildings being of such an aggregate size as to impose an unacceptable risk on the unlimited area building. The primary consideration in allowing buildings of unlimited area is that the complete perimeter (in the case of the exceptions at least 75%) be open and available for fire department access and operations. Multiple buildings adjacent to an unlimited area building would compromise this theory.
 
The 3 story building that was built against this UAB was built in the last two years. I don't see in the current code where you can occupy 25% of the open perimeter. the current code states you can reduce the 60' open perimeter down to 40', not down to zero which is what a fire wall essentially would do.
 
Correct....Call OSBI for guidance...? You mind saying what Town? Good on you to bring this up and try to solve it...

Hyrax4978 said:
The last addition was put on less than two years ago. put on by someone who is known for cutting corners. So im trying to figure out how to do an addition for the client and be code compliant. Im stuck at this point.
I don't see how you can have an unlimited area building if you have a separate 3 story building attached and separated by a fire wall.
Click to expand...

Hyrax4978 said:
The 3 story building that was built against this UAB was built in the last two years. I don't see in the current code where you can occupy 25% of the open perimeter. the current code states you can reduce the 60' open perimeter down to 40', not down to zero which is what a fire wall essentially would do.
Click to expand...
 
Have a conference call with the local this afternoon. Rather not say. Trying not to throw anybody under the buss. Just want to do what is right.
 
Follow up:
Spoke to B.O. basically said we are in a bit of a pickle. The last addition the owner put on negated the UAB they had going for them.
Based on further inspection. of the 3 hour wall. Its actually not a new wall. its an old wall. Just an interior 3 hr separation, not a true fire wall.
Major issues aside with the last code summary they had; At this point I don't see any way to get any additional square footage as they are basically maxed out when you look at the sum of the ratios. sum of the ratios = 0.984....
 
Well, without spending a bunch more time (and may not see a return) its tough to see if its compliant as is. The last code summary has many issues at best. Based on the info at hand... Best case scenario they are at a 0.984 sum of ratios. But if you really look at the code summary, which also includes some A-2 uses that can't really be determined on if its accessory or not its really hard to tell. Best case scenario they are ok and 0.984. But there is a high probability if I keep digging they may not be compliant as is. Either way, the last addition really hindered the client who could have been classified as UAB when they put on that third floor, which could have easily been done on two slightly larger floors. Looking at budgeting a fire wall i think might be the only option for an addition, and i have to look at how that will affect the existing buildings open perimeter increases. with the 0.984 if i take away open perimeter that might be the stray that breaks the camels back on the existing building.
 
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