How to count buildings on same lot

[brudgers]

It considers it several buildings as well.

 

[texasbo]

It considers it several buildings as well.

Negative. It gives you the option to consider it several buildings. It also gives you the option of considering it a single building. You don't get to pick and choose.

Think about it: if each building were allowed to meet different requirements, and still be considered one building, then why have opening protection and wall protection in the first place. You only get the benefits of 503.1.2 if the provisions applicable to the AGGREGATE are applicable to EACH building.

 

[texasbo]

501.1 Scope. The provisions of this chapter control the height and area of structures hereafter erected and additions to existing structures.

Whoa.... just because the chapter regulates additions, doesn't mean that everything is an addition.... It also regulates existing buildings. That doesn't mean everything is an existing building.

Again, 503 says nothing about new, existing, additions, or alterations. It says that two or more BUILDINGS can be considered a SINGLE building. And, it says the requirements for the aggregate apply to the parts.

 

[alora]

Whoa.... just because the chapter regulates additions, doesn't mean that everything is an addition.... It also regulates existing buildings. That doesn't mean everything is an existing building.

Understood.

Again, 503 says nothing about new, existing, additions, or alterations.

Correct. One makes it apply as they need to based on the scope defined in 501.1 -- whether for additions or new construction.

It simply says the requirements for the aggregate apply to the parts.

It actually says:

...The provisions of this code applicable to the aggregate building shall be applicable to each building.

"This code" meaning the entire codebook, including Chapter 34.

"Aggregate building" meaning the existing building 'plus additions' as described in Chapter 34.

 

[texasbo]

The provisions of "THIS CODE" applicable to the aggregate building shall be applicable to each building."This code" meaning the entire codebook, including Chapter 34.

Fair enough.

So you're saying then, that each part of this aggregate building only has to comply with the code provisions for that portion of the building?

And you're also saying that Ch 34 is applicable to the aggregate building?

And lastly, am I understanding you correctly that your opinion is that if each of these 3 buildings complies with "this code" on its own, then they get the benefits of 503.2.1, and separation, wall ratings, opening protection, etc are not required?

 

[alora]

Fair enough. So you're saying then, that each part of this aggregate building only has to comply with the code provisions for that portion of the building?

And you're also saying that Ch 34 is applicable to the aggregate building?

And lastly, am I understanding you correctly that your opinion is that if each of these 3 buildings complies with "this code" on its own, then they get the benefits of 503.2.1, and separation, wall ratings, opening protection, etc are not required?

Depends.

I think the key word for what you're asking is "applicable".

I also think the order of the applicability is key: what applies to aggregate building >>> applies to each building; not vice versa.

If the aggregate building is being modified to include a new building addition, then the new building has to meet the provisions required for new construction.

Likewise, if the existing aggregate building is being added to, then the provisions of 3403.1 will affect each building.

Did I understand the question correctly?

 

[texasbo]

It seems that the above excerpted section considers an existing building an "addition" to an existing building."An existing building" is singular, meaning literally one building.

"plus additions" is plural and defined in the first sentence of 3403.1 and would, therefore, include all remaining existing building and new buildings.

And, those "additions or alterations" would have to meet the requirements for new construction.

OK, so let me get this straight: 503.1.2 says that two or more buildings on the same lot may be regulated as separate buildings or may be considered as portions of a single building...

But what you're saying it really means is that when there are two or more buildings on a lot, that one is considered existing, and the rest of the buildings are considered additions?

 

[texasbo]

If the aggregate building is being modified to include a new building addition, then the new building has to meet the provisions required for new construction.

OK, this is what I was looking for, and sorry the posts are starting to wind together.

Where in the world are we getting "addition" from?

503 addresses multiple buildings on a lot.

What we have here are multiple buildings on a lot.

This isn't an "addition" this is a third building. 503 says we can consider them separately, or consider them together. Why are we polluting the discussion with "additions, alterations, Ch 34," etc? The example we've been discussing is EXACTLY what the code intends to address, and it does so very simply.

Edit: if the code language specifically said to treat new buildings as additions, I'd be fine with that. My point is that the code doesn't say to do it that way.

 

[Papio Bldg Dept]

Depends.I think the key word for what you're asking is "applicable".

I also think the order of the applicability is key: what applies to aggregate building >>> applies to each building; not vice versa.

If the aggregate building is being modified to include a new building addition, then the new building has to meet the provisions required for new construction.

Likewise, if the existing aggregate building is being added to, then the provisions of 3403.1 will affect each building.

Did I understand the question correctly?

Thanks alora and tex for putting your thought processes out there. I find them very helpful in understanding the code. I believe there is also an exception for change of occupancy, if the occupancy is less hazardous, but again, this is new to me, and I am not sure if it is "applicable."

 

[Papio Bldg Dept]

OK, this is what I was looking for, and sorry the posts are starting to wind together. Where in the world are we getting "addition" from?

503 addresses multiple buildings on a lot.

What we have here are multiple buildings on a lot.

This isn't an "addition" this is a third building. 503 says we can consider them separately, or consider them together. Why are we polluting the discussion with "additions, alterations, Ch 34," etc? The example we've been discussing is EXACTLY what the code intends to address, and it does so very simply.

Edit: if the code language specifically said to treat new buildings as additions, I'd be fine with that. My point is that the code doesn't say to do it that way.

Section 202: Definitions: Addition. An extension or increase in the floor area or height of a building or structure.

In this case/example, multiple buildings are being reviewed as one building with a floor area increase. I believe that is a rational interpretation of the code. Please clarify if you think otherwise. It is an interesting debate nevertheless.

 

[alora]

OK, this is what I was looking for, and sorry the posts are starting to wind together. Where in the world are we getting "addition" from?

503 addresses multiple buildings on a lot.

What we have here are multiple buildings on a lot.

This isn't an "addition" this is a third building. 503 says we can consider them separately, or consider them together. Why are we polluting the discussion with "additions, alterations, Ch 34," etc? The example we've been discussing is EXACTLY what the code intends to address, and it does so very simply.

Edit: if the code language specifically said to treat new buildings as additions, I'd be fine with that. My point is that the code doesn't say to do it that way.

Some definitions:

ADDITION. An extension or increase in floor area or height of a building or structure.ALTERATION. Any construction or renovation to an existing structure other than repair or addition.

BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy.

Using scope description of 501.1, a new building is "an extension or increase in floor area or height" of an existing aggregate building.

In other words, an "addition".

 

[Big Mac]

Back to the original question, Yes multiple buildings (structures) on the same lot may be considered as one, IF all combined buildings (structures) are within the allowable floor area and height limitations for a single building as established by code. That might be two, three, four, five, etc. separate structures. After you have reached the maximum allowable area for the 'Use Group B' occupancies, you need to start over. That doesn't mean that a second set of buildings on this site may not also be considered as one building. At that point however, all clusters of buildings (structures) considered as one building would be required to have a physical or fire-resistive separation as required by the building code from the other clusters of buildings. It is conceivable that you may have 12 physically separated buildings (structures) on a site but only have two clusters of buildings (structures) that comprise two code compliant buildings with regard to allowable floor area.

If that happens each individual structure within each cluster of buildings would need to meet the requirements of Section 503.1.2 including the last sentence which reads "The provisions of this code applicable to the aggregate building shall be applicable to each building (structure).

 

[texasbo]

Some definitions:Using scope description of 501.1, a new building is "an extension or increase in floor area or height" of an existing aggregate building.

In other words, an "addition".

So the construction of a storage building 10' away from my house is an "addition"? And nowhere in the code is the term "existing aggregate building". It's kinda like being pregnant; it's either an aggregate building or it's not. More specifically, it's either one aggregate building, or three separate buildings. There is no "existing", or "new," or "addition", or "alteration".

This is in response to Papio too:

If this was an expansion of a building, it would be an addition.

But it's not; it's a new building; a third building. And the code gives us the choice to decide whether we consider it 3 separate buildings, or one big building.

In other words, we get the choice of pretending it's a single building.

But pretending it's one big building is where the code stops. It doesn't give us the authority (or the permission) to pretend anything else.

 

[alora]

So the construction of a storage building 10' away from my house is an "addition"?

I would say yes, if you want to use the provision of 503.1.2 in that way; it's your choice.

If this was an expansion of a building, it would be an addition.But it's not; it's a new building. We get to decide whether we consider it 3 separate buildings, or one big building.

In other words, we get the choice of pretending it's a single building.

But pretending it's one big building is where the code stops. It doesn't give us the authority (or the permission) to pretend anything else.

Construction a new detached building is "an extension or increase in floor area or height" of an existing building, IF you're using 503.1.2 in that manner.

So then, a serious question, at what point do the provisions of "this code" stop with regard to an "aggregate building"?

Which chapters/sections specifically apply to - or don't apply to -- 'aggregate buildings'?

 

[texasbo]

I would say yes, if you want to use the provision of 503.1.2 in that way; it's your choice.Construction a new detached building is "an extension or increase in floor area or height" of an existing building, IF you're using 503.1.2 in that manner.

Well congratulations; you just won. Because if you believe that every building built is an addition to another building, then I have no argument. Can I believe that every building built has a refrigerator full of Guiness waiting for me?

 

[texasbo]

So then, a serious question, at what point do the provisions of "this code" stop with regard to an "aggregate building"?Which chapters/sections specifically apply to - or don't apply to -- 'aggregate buildings'?

That's what I was saying earlier; don't all provisions that would apply if it was a single building apply to the individual buildings, if they are considered as an aggregate building?

And I think that's where most people fall short when applying 503; they neglect to notice that last sentence.

 

[alora]

Can I believe that every building built has a refrigerator full of Guiness waiting for me?

Unless the fridge has left the building.

 

[texasbo]

^ Great..

Here's something else to consider:

Let's say we have our three buildings and we're considering them an aggregate building. Let's say they are separated 5' from each other, but that's ok, because it is considered one building, so no rated exterior wall or separation required.

Now, let's say that one of the buildings has an occupancy that requires an occupancy separation from the occupancy in another building. What do you do? Occupancy separation? One building or both? Is 5' equal to an occupancy separation?

Straying a little OT only because OP said they liked to see the discussion.

 

[Papio Bldg Dept]

So the construction of a storage building 10' away from my house is an "addition"? And nowhere in the code is the term "existing aggregate building". It's kinda like being pregnant; it's either an aggregate building or it's not. More specifically, it's either one aggregate building, or three separate buildings. There is no "existing", or "new," or "addition", or "alteration".This is in response to Papio too:

If this was an expansion of a building, it would be an addition.

But it's not; it's a new building; a third building. And the code gives us the choice to decide whether we consider it 3 separate buildings, or one big building.

In other words, we get the choice of pretending it's a single building.

But pretending it's one big building is where the code stops. It doesn't give us the authority (or the permission) to pretend anything else.

I am sticking by it being an extension of the floor area, and thereby an addition to that building, (insert pregnant pause here) IF on chooses to view it as a single building. This type of design gives an option to consider multiple buildings as one building. In doing so, the existing building(s) would be one part of the aggregate and the new building(s) would be the other, in this case the addition). Brudgers I believe sees it differently, in that only one of the existing buildings would be permitted to be considered existing, and all others are new additions. Not sure I am in complete agreement, but I do understand the logic here (and it is not farmers, of which I am familiar, being one myself). (sigh) Furthermore, if it exceeds the allowable area with frontage increases and sprinklers are required to comply with allowable area, the existing portion would then (Chapter 34) need to be designed in accordance with "this code," which includes Chapter 34. As much as we would like to dismiss 34, it is required by this code for all work applicable to existing buildings. In this case, it was noted that multiple buildings are existing, and area would added to these as one building, even though they are so many feet apart. (breath)

Okay, so does that help shed some light on the addition argument?

 

[Papio Bldg Dept]

^ Great..Here's something else to consider:

Let's say we have our three buildings and we're considering them an aggregate building. Let's say they are separated 5' from each other, but that's ok, because it is considered one building, so no rated exterior wall or separation required.

Now, let's say that one of the buildings has an occupancy that requires an occupancy separation from the occupancy in another building. What do you do? Occupancy separation? One building or both? Is 5' equal to an occupancy separation?

Straying a little OT only because OP said they liked to see the discussion.

or, (not sure we want to go here yet, but what the heck) what if you decided to sprinkle instead of a fire rated separation for occupancy? Sprinkle all buildings? Sprinkle the exterior areas between the buildings? Or like you said, would you allow fire separation distances to serve as occupancy separations? interesting direction for the discussion, but I think we should solve addition question first.

 

[texasbo]

As much as we would like to dismiss 34, it is required by this code for all work applicable to existing buildings. In this case, it was noted that multiple buildings are existing, and area would added to these as one building, even though they are so many feet apart. (breath)Okay, so does that help shed some light on the addition argument?

If in fact you consider two of the three buildings to be additions, then you are bound to look at how they affect the third building that you randomly choose to be the "existing" one.

I will choose to go by the letter of 503, and consider multiple buildings on a lot to be a single aggregate building, and apply the code that applies to the aggregate to each portion.

 

[texasbo]

Sprinkle all buildings?

If sprinklers are the direction you choose, then I firmly believe that 503.1.2 requires all buildings. The provisions of this code that apply to the aggreg... well, you know the rest.

 

[Papio Bldg Dept]

So then, a serious question, at what point do the provisions of "this code" stop with regard to an "aggregate building"?Which chapters/sections specifically apply to - or don't apply to -- 'aggregate buildings'?

I would say if I am considering this an addition to an existing structure, then the provisions of "this code" stop when Chapter 34 tells me so, and I believe that is the intent of the IBC Chapter 34\portion of "this code." Otherwise it would only be in "that code," affectionately known as IEBC. There is a choice to be made by the designer in Chapter 5. Once the designer makes that choice, you live with the choice. In this case, the choice is to take an existing building(s) and add area to it, by adding another building(s), and considering 1 building in order to avoid fire-rating exterior assemblies. I don't believe you can ignore the fact that a portion of this example is existing, the new part is an extension of the building area as defined by this codes definition for "addition," and thus should be treated as such in Chapter 34.

 

[gbhammer]

I am new to the forum and love reading all the responses, even Brudgers.

I 'get' that the DP can take this in so many directions that it can make a head spin, but the original question was simple. Where do you stop when treating the buildings on the same lot as one building?

When they no longer have an effect upon one another.

For this example: 2 of the buildings would be 35-38 feet away, the other building would be 18 feet away.

It is a type VB construction, B use group.

Table 602: 10' or less separation required. greater than 10' no rating required

Create a lot line between them and only the building that is within 18' would require a 1 hour rating, unless they are treated as one building.

Even then the two buildings are not required to be separated because they are the same use group Table 508.4 they do not exceed the area limitations and even if they were of mixed use they may not need to be separated if they meet the strictest requirements of chapter 4 or 9.

There is no reason whatsoever to even look at chapter 34 or the IEBC.

Even though it is great to read your thoughts on the subject.