How to count buildings on same lot

[texasbo]

Texasbo, please help me understand this. 503.1.2 was added to the code to address an inconsistancy in the code where two buildings within 10' of each other would need to fire-protect their adjacent exterior openings/walls based upon the imaginary property line and fire separation distances, however if they were connected by a roof or wall, and their aggregate area was still under the allowable areas, they would then be considered an addition and would not require fire-protection of those interior walls. My understanding is, for consistency sake, you either consider it one building under 503.1.2, or you consider it two buildings. You don't get to consider it as one building for allowable areas and then default back to it being two separate buildings. You make the choice of how you want to handle because there are benefits to each way, and then you treat as such per the code regarding your choice. If you take an existing building, and want to ADD a building to it, whether it is 2' or 20' away, and consider them as one building, then you treat the new part as an addition (Chapter 34/IEBC can then be applied if necessary, for example if the existing building were to experience a change in occupancy, or did not meet the type of construction or structural requirements for new construction of the current code when the new building is added). If you want to build an new building next to an existing building and maintain them as separate, then you treat them as such and fire protect the exterior walls/openings per the code. In other words, adding a building to a lot with an existing building, and wanting to consider it as one building, requires that it be treated as a single building when applying the code. This is not pulling a rabbit out of a hat. It is fundamental difference of interpretation, and I do not believe yours is entirely consistent with the code, by definition. You have not convinced me otherwise, and I do not see the rational for applying 503.1.2, calling it a single building to avoid fire protection of exterior walls, and then reverting back to separate building application of the code. In the words of the great and almighty Spock, 'That is illogical sir."

Everything you say is correct, except you're still using the word "addition", which is not the subject of 503.1.2.

I absolutely agree that you can consider multiple buildings as a single building, to get the benefits of 503.1.2. However, it is just that, a single building, not multiple buildings, and not a building with additions.

The intent of 503.1.2 is to not penalize multiple buildings that are close together if they could have been a single building under one roof. You are right, it would be ridiculous to require rated exterior walls, etc, between three 500 sq ft buildings, when one 1500 square foot building would be just fine. However, it is not the intent of the code to allow you to only make part of this "single building" comply with the code.

If that were the case, a wiley architect could design one building, then come in the next day with plans to put another one right beside it, and claim that he would have to do nothing to upgrade the original building that just got co'd the previous day.

You have a choice: consider them separately, or pretend they are all a single building. In the first case, you assume property lines between the buildings, and you need not modify the existing buildings (unless of course the property line is too close to an exterior wall). In the second case, you review all three buildings as if they were a single building. You don't get to mix and match. In other words you don't get to consider it a single building, but make only part of it comply.

To beat the dead horse: read 503.1.2 again - it says that you can consider them as separate buildings or as one building. The key word is building. There is no "addition" anywhere in this very specific section of the code. One member planted that seed, and a couple of you have picked up on it, but it's just not there.

 

[Papio Bldg Dept]

Applying Chapter 34 or the IEBC does not automatically require the existing building to comply with todays code. An evaluation would need to be done. ​

Thank you MT. Apparently you have a managed to say what I can not. The only thing I would change about 3410.2.3, is to add the following sentence to the end:

Where a fire wall is not provided between the addition and the existing building, the addition shall be considered as part of that building.

Here goes my lunch break.

The commentary for 3403.1 is as follows (take it for what you want):

The purpose of this section is to establish guidelines for additions or alterations to existing buildings and structures.

An addition is an increase in the area to an existing building. When a new building is erected immediately adjacent to an existing building, and they are separated by a fire wall, it is considered a separate building, not an addition to the existing structure. The new building must be designed to comply with the technical provisions of Chapters 1 through 33, not with the provisions of this chapter. The existing building must be evaluated considering the elimination of the adjacent open space now occupied by the new building.

An existing structure that is of a type of construction that does not comply with the height and area limitations of Table 503 may not be added to unless the type of construction is upgraded, or the allowable building height and area are increased through the addition of a sprinkler system throughout both the existing building and the addition. (THIS SEEMS LIKE AN IDEA OF WHY CHAPTER 34 WOULD COME INTO PLAY)

A building with a proposed addition is to be evaluated based on the type of construction of the existing building or the addition, whichever is the lower type. (MAYBE ANOTHER REASON 34 SHOULD BE LOOKED AT) When reviewing for compliance with Table 503, see Section 602.1.1.

It just seems to me Chapter 34 should get some more consideration, and not be so readily dismissed. Section 3410 actually helps you, in that it gives you alternatives for existing building compliance so you don't have to destroy the existing building.

 

[Papio Bldg Dept]

To beat the dead horse: read 503.1.2 again - it says that you can consider them as separate buildings or as one building. The key word is building. There is no "addition" anywhere in this very specific section of the code. One member planted that seed, and a couple of you have picked up on it, but it's just not there.

Thank you for your continued effort.

Well at least we are now down to the root of our disagreement. I am holding to my interpretation that, if you treat it as one building, then the EXISTING portion of that one building, is now referred to Chapter 34. The new portion is now an addition shall be reviewed for compliance with technical provisions for new construction, however, the existing portion(s) may be allowed alternative compliance options based upon EVALUATION of the existing buildings per Section 3410, in order to determine which aspects of the EXISTING building need to be upgraded.

 

[brudgers]

I agree with texasbo. I have no idea why Chapter 34 or the IEBC would be in play. You are evaluating all buildings on a single lot OR providing proper fire separation distance by lot lines, imaginary or real, individual or clustered, between buildings. To prevent conflagration, maybe? From the sound of some of the responses, I suppose you're only limited by how much the client is willing to see destroyed.

The reason existing building requirements come into play is because they are being added onto by the new construction under the scenario proposed in the original post.

 

[texasbo]

The reason existing building requirements come into play is because they are being added onto by the new construction under the scenario proposed in the original post.

Except that it is not being added onto. It is now being considered as a single building per 503.1.2.

 

[texasbo]

Thank you for your continued effort.Well at least we are now down to the root of our disagreement. I am holding to my interpretation that, if you treat it as one building, then the EXISTING portion of that one building, is now referred to Chapter 34. The new portion is now an addition shall be reviewed for compliance with technical provisions for new construction, however, the existing portion(s) may be allowed alternative compliance options based upon EVALUATION of the existing buildings per Section 3410, in order to determine which aspects of the EXISTING building need to be upgraded.

Right; that seems to be the extent of our disagreement, and I don't think either of us is going to convince the other. You are reviewing it as an addition to an existing building, and I am reviewing it as multiple buildings on a single lot being considered as a single building. I don't interpret 503.1.2 to differentiate whether the buildings are existing or new; if you want the benefits of that section, you must consider it as a single building.

Again, refer to my example of the applicant, for whatever reason, wants to do no work, but just wants us to consider three existing separate buildings as one. No problem, I'm going to review it as a single building, and tell him what he needs to do to comply with the code. I'm not going to arbitrarily pick one as the existing building and call two an addition as brudgers would. All bets are off, and per 503.1.2, I'm reviewing it as a single building.

Now, If I were making this case for brudgers, I could come up with a really strong specific argument, that would be tough to defend. He hasn't done it yet, but we'll see if it comes to him.

 

[Papio Bldg Dept]

Except that it is not being added onto. It is now being considered as a single building per 503.1.2.

T-bo...regardless of where we stand on the addition/new building definition (semantics of a neglible value), the existing building still needs to be evaluated when you put new construction within its fire separation distance, or treat it as a single building and verify its allowable areas. If it doesn't comply, it needs to be upgraded and Chapter 34 is the Section of code you use for existing structures specifically for this reason.

 

[brudgers]

Except that it is not being added onto. It is now being considered as a single building per 503.1.2.

When the permit is pulled for the new construction the code analysis is based upon an existing aggregate building. When construction commences, the existing aggregate building receives an addition.

You don't start with the end state.

 

[Papio Bldg Dept]

Again, refer to my example of the applicant, for whatever reason, wants to do no work, but just wants us to consider three existing separate buildings as one. No problem, I'm going to review it as a single building, and tell him what he needs to do to comply with the code. I'm not going to arbitrarily pick one as the existing building and call two an addition as brudgers would. All bets are off, and per 503.1.2, I'm reviewing it as a single building.

My position on your example, all three are still existing buildings, and should be EVALUATED in Chapter 34 as ONE EXISTING BUILDING.

In the OP, the applicant is adding multiple existing buildings together and building new construction to be evaluated as a single building. If the new construction is to be combined with existing buildings to form one building, then the new construction can be evaluated as an addition, which would be required to meet the tech. provisions for new construction, if that that portion is of a lesser hazard than the existing.

I will leave it at that, and rest my case unless anyone has questions regarding Chapter 34.

 

[texasbo]

T-bo...regardless of where we stand on the addition/new building definition (semantics of a neglible value), the existing building still needs to be evaluated when you put new construction within its fire separation distance, or treat it as a single building and verify its allowable areas. If it doesn't comply, it needs to be upgraded and Chapter 34 is the Section of code you use for existing structures specifically for this reason.

We're going in circles. This is the part we agreed that we disagree on. Since we're talking about considering it a single building, fire separation distance is irrelevant. And I understand you review it as an addition to an existing building. I wouldn't. I do not recognize any part of it as an existing building, nor would I apply 34 or IEBC. I would review it as a single building, just as if it was all fresh off the drafting board, and require all portions of that single building to comply with all portions of the code.

You can bring me three 100 year old buildings, one 100 year old building and two new buildings, or three new buildings, but if you want the "single building" benefits afforded by 503.1.2, I'm going to review each of them exactly the same, as a single building under all sections of the current code (does the new "single building" meet allowable heights, areas, fire protection, exits, etc, with no consideration for 34 or IEBC at all). 503.1.2 doesn't care how old they are if you want the leniency it provides. If you don't want its benefits, then sure, I'll review the existing stuff under 34.

 

[mtlogcabin]

the existing building still needs to be evaluated when you put new construction within its fire separation distance,

The only evaluation would be allowable openings and is the wall rated or not. Remember you can get within 5 ft and only have to rate the wall from the inside.

or treat it as a single building and verify its allowable areas. If it doesn't comply,

then it doesn't comply with the allowable areas. The fact the existing building does not comply with egress or accesibility are not part of the requirements of 503.You have a 1500 sq ft V-B office building built in 1969 under a Legacy Code and they are going to place a 200 sq ft V-B storage shed next to it to store old files in. Just exactly will the IEBC or Chapter 34 require the existing building to comply with.

 

[Papio Bldg Dept]

We're going in circles. This is the part we agreed that we disagree on. Since we're talking about considering it a single building, fire separation distance is irrelevant. And I understand you review it as an addition to an existing building. I wouldn't. I do not recognize any part of it as an existing building, nor would I apply 34 or IEBC. I would review it as a single building, just as if it was all fresh off the drafting board, and require all portions of that single building to comply with all portions of the code. You can bring me three 100 year old buildings, one 100 year old building and two new buildings, or three new buildings, but if you want the "single building" benefits afforded by 503.1.2, I'm going to review each of them exactly the same, as a single building under all sections of the current code (does the new "single building" meet allowable heights, areas, fire protection, exits, etc, with no consideration for 34 or IEBC at all). 503.1.2 doesn't care how old they are if you want the leniency it provides. If you don't want its benefits, then sure, I'll review the existing stuff under 34.

Thanks Tex. For the first time I think I wholly understand where you are coming from. I will let that sink in overnight. Thanks again.

 

[Papio Bldg Dept]

The only evaluation would be allowable openings and is the wall rated or not. Remember you can get within 5 ft and only have to rate the wall from the inside.then it doesn't comply with the allowable areas. The fact the existing building does not comply with egress or accesibility are not part of the requirements of 503.

I am saying that if it doesn't comply with allowable areas, but qualifies under a sprinkler increase, then the existing building would also need to be sprinklered.

You have a 1500 sq ft V-B office building built in 1969 under a Legacy Code and they are going to place a 200 sq ft V-B storage shed next to it to store old files in. Just exactly (what) will the IEBC or Chapter 34 require the existing building to comply with.

That depends on whether you want to consider the shed and the existing office as ONE BUILDING.

Texasbo would then say you have to bring all buildings lumped together as one up to current codes.

I am saying that you would not necessarily have to hold the existing portions to all of the new construction provisions, because you could use the existing building code to evaluate the existing portions of the ONE BUILDING aggregate. The shed would, as I consider it, or Texasbo considers it need to comply with new construction provisions.

If you want to keep them as two buildings, then it is just a fire wall/openings issue for FSD, and all the other MOE, Accessibility, etc provisions would not apply to the existing unless they are affected by the new construction (i.e., access to public right of way if MOE exits through fire wall, etc.).

 

[TJacobs]

We're going in circles. This is the part we agreed that we disagree on. Since we're talking about considering it a single building, fire separation distance is irrelevant. And I understand you review it as an addition to an existing building. I wouldn't. I do not recognize any part of it as an existing building, nor would I apply 34 or IEBC. I would review it as a single building, just as if it was all fresh off the drafting board, and require all portions of that single building to comply with all portions of the code. You can bring me three 100 year old buildings, one 100 year old building and two new buildings, or three new buildings, but if you want the "single building" benefits afforded by 503.1.2, I'm going to review each of them exactly the same, as a single building under all sections of the current code (does the new "single building" meet allowable heights, areas, fire protection, exits, etc, with no consideration for 34 or IEBC at all). 503.1.2 doesn't care how old they are if you want the leniency it provides. If you don't want its benefits, then sure, I'll review the existing stuff under 34.

:agree Exactly.

 

[mtlogcabin]

I am saying that if it doesn't comply with allowable areas, but qualifies under a sprinkler increase, then the existing building would also need to be sprinklered

Agree under Chapter 5 you could take the aggregate area and use that and apply the frontage increases and if that is not enough then you would have to sprinkle the new AND existing building to get the sprinkle increase.

 

[fatboy]

":agree Exactly. "

Yup...........

 

[Papio Bldg Dept]

":agree Exactly. "Yup...........

well all be darned if I ain't a pig in the mud on this one. good thing I enjoyed it. Thanks for everyone's feedback.