How to count buildings on same lot

[righter101]

IBC 503.1.2

503.1.2 Buildings on same lot. Two or more buildings on

the same lot shall be regulated as separate buildings or shall

be considered as portions of one building if the building

height of each building and the aggregate building area of

the buildings are within the limitations of Table 503 as modified

by Sections 504 and 506. The provisions of this code

applicable to the aggregate building shall be applicable to

each building.

This allows separate buildings to be considered as a single building.

Question: if I have say, a dozen "B" occupancies on the same property and am putting a new building, also a "B" in close proximity to two of the existing structures (these are all 800-1500 sq ft), can I group 2 or 3 of them together and consider it a "single" structure under the 503.1.2 provisions, then consider all the others separate, or do I need to consider all the buildings on the property if I am going to use this???

I have my idea but wanted to get feedback and opinions.

 

[fatboy]

What separation do you have from the others that you don't want to consider?

 

[texasbo]

The code says "separate buildings", it doesn't say "how many" separate buildings.

While I'm sure it will be debated to high holy hell, I would have no problem whatsoever allowing various groups of buildings to be considered as single buildings, while counting others individually. Provided of course all separation/opening protection/allowable heights and areas work for the combinations.

In other words, if you have a group of church buildings that are all Type IIA and right at the limit for allowable height and area when considered together , there should be no problem adding a separate VB storage building provided there is adequate separation from the IIA complex.

 

[righter101]

It is a type VB construction.

There are 3 adjacent buildings to the new one.

They are 800-1500 sq ft.

with the proposed configuration, 2 of the buildings would be 35-38 feet away (Fire separation distance of 15-20, allowing 25% unprotected openings). The other building would be 18 feet away and would require the openings on the existing building to be protected. There are no openings on the closest side of the new building.

I feel if I consider 2 of them as a single building and verify that the remaining adjacent buildings are OK for separation and protected openings, there wouldn't be an issue.

 

[fatboy]

I would agree.

 

[texasbo]

It is a type VB construction.There are 3 adjacent buildings to the new one.

They are 800-1500 sq ft.

with the proposed configuration, 2 of the buildings would be 35-38 feet away (Fire separation distance of 15-20, allowing 25% unprotected openings). The other building would be 18 feet away and would require the openings on the existing building to be protected. There are no openings on the closest side of the new building.

I feel if I consider 2 of them as a single building and verify that the remaining adjacent buildings are OK for separation and protected openings, there wouldn't be an issue.

I agree as well, but would the aggregate area of ALL of the buildings bust the allowable area?

 

[brudgers]

It is a type VB construction. There are 3 adjacent buildings to the new one. They are 800-1500 sq ft. with the proposed configuration, 2 of the buildings would be 35-38 feet away (Fire separation distance of 15-20, allowing 25% unprotected openings). The other building would be 18 feet away and would require the openings on the existing building to be protected. There are no openings on the closest side of the new building. I feel if I consider 2 of them as a single building and verify that the remaining adjacent buildings are OK for separation and protected openings, there wouldn't be an issue.

So long as the existing building(s) are upgraded as required by the addition - i.e. the provisions of IEBC would have to be applied to the original building(s) based on the extent of the addition. In the case of two existing buildings + one new building, one existing building would receive both additions (one new building and one existing building).

The existing building classified as an addition would have to meet current code for new construction.

The new building would have to meet current code for new construction.

A case could also be made that the building receiving the addition would need to meet current code for new construction in order to take advantage of chapter 5.

 

[texasbo]

There is absolutely nothing in the code that states that when considering two existing buildings as one, per 503, that one of the existing buildings is considered an "addition" to the other existing building.

 

[TJacobs]

I would count every building on the lot. I would also allow them to evaluate a group of buildings with imaginary lot lines showing proper separation separately from the others.

 

[brudgers]

There is absolutely nothing in the code that states that when considering two existing buildings as one, per 503, that one of the existing buildings is considered an "addition" to the other existing building.

Other than 3403.1 you are correct.

 

[texasbo]

Other than 3403.1 you are correct.

Except nowhere in the original post did it say that there were any alterations or additions to an existing building.

To say that 34 applies to existing buildings that are not being altered because we are pretending they are one building, is like requiring a contractor to plat an imaginary property line.

3401 Scope The provisions of this chapter shall control the alteration, repair, addition, and change of occupancy of existing structures.

It doesn't say "this chapter shall apply to existing buildings that are just sitting there, because we're pretending they are one building".

 

[brudgers]

Except nowhere in the original post did it say that there were any alterations or additions to an existing building. To say that 34 applies to existing buildings that are not being altered because we are pretending they are one building, is like requiring a contractor to plat an imaginary property line. 3401 Scope The provisions of this chapter shall control the alteration, repair, addition, and change of occupancy of existing structures. It doesn't say "this chapter shall apply to existing buildings that are just sitting there, because we're pretending they are one building".

Yes, you found it, now the next step is for you to apply it. Under 503.1.2 the new building would be an addition to each of the existing structures. Hence 3403.1 applies.

 

[texasbo]

. Under 503.1.2 the new building would be an addition to each of the existing structures.

You are either reading from a different code, or making up your own. 503.1.2 says nothing of the sort.

Your exact words: "In the case of two existing buildings + one new building, one existing building would receive both additions (one new building and one existing building)."

Since when is an existing building an addition to an existing building?

 

[brudgers]

You are either reading from a different code, or making up your own. 503.1.2 says nothing of the sort. Your exact words: "In the case of two existing buildings + one new building, one existing building would receive both additions (one new building and one existing building)." Since when is an existing building an addition to an existing building?

When they are combined with a new building to become one building under the current code. And of course, the new building is what opens up the can of worms.

Because there is no question that it is an addition under the scenario described.

 

[texasbo]

When they are combined with a new building to become one building under the current code. And of course, the new building is what opens up the can of worms.

Because there is no question that it is an addition under the scenario described.

Again, you are making up code. Nowhere does the code say that an existing building, under any circumstances, is to be considered an addition pursuant to 503. It's just not there.

Under that logic, two existing buildings that comply in every way except for having rafter spans that met a previous code, now have to be modified because they are being considered a single building, because you say one must now be called an addition (due to the new building ). Read the code, use the code, don't make up code.

 

[righter101]

I think I understand Brugers point. If I want to use the provisions of CH5 to consider several of these as a single building, then in effect, that "single building" is now receiving an "addition".

I would buy in to that. They can comply with 3403.1 by having the propsed new construction meet all current codes.

This is a small University extension campus. There are a bunch of individual buildings. The area in question there are 9 or 10 "B" occupancies (Lab buildings), varying distances apart. They are proposing to add another, about 1500 sq ft. The dorm rooms, eating hall, and other structures, while on the same lot, are far enough away to not affect this cluster.

What drove my original question is the architect situated this building perfectly so there was no fire separation issue, specific to opening protection. The University, however, wants to rotate the building about 15 degrees so it lines up better with the rest of the structures. In doing this, however, one side of the building has the fire separation distance reduced to a condition that would require opening protection.

The total area of all the "B"'s in this cluster could very well be under the CH5 allowable ht/area, using a frontage modification.

I was just wondering if I have to consider every single building on the lot, or if I can consider, say, 4 out of 10 of these as a single building, or 3 or some other variation of that.

Basically, does it matter where I draw the line to consider these as a single structure.

As always, I appreciate the discussion because it brings up things I had not considered.

 

[texasbo]

They can comply with 3403.1 by having the propsed new construction meet all current codes.

Actually, according to brudgers, it's not JUST the new building that has to comply with all requirements for new construction. In his mind, if you have 2 existing buildings and one new building, one of the existing buildings has to comply with all requirements of a new building.

"The existing building classified as an addition would have to meet current code for new construction."

Which is just wrong.

And he doesn't even take for granted that the OTHER existing building can just get by with Ch 34:

"A case could also be made that the building receiving the addition would need to meet current code for new construction in order to take advantage of chapter 5."

He got some of the rest of it right, more or less.

And in terms of where you assume property lines, and how you divide up existing buildings and/or groups of existing buildings and new buildings is up to you and/or the designer.

 

[Papio Bldg Dept]

texasbo and brudgers conversation reminds me of the conversation int MP's Holy Grail between the two castle guards charged with making sure no one escapes.

 

[Papio Bldg Dept]

So long as the existing building(s) are upgraded as required by the addition - i.e. the provisions of IEBC would have to be applied to the original building(s) based on the extent of the addition. In the case of two existing buildings + one new building, one existing building would receive both additions (one new building and one existing building).

The existing building classified as an addition would have to meet current code for new construction.

The new building would have to meet current code for new construction.

A case could also be made that the building receiving the addition would need to meet current code for new construction in order to take advantage of chapter 5.

I always enjoy reading Chapter 34 & the IEBC. I have read 3410.2.3 several times and never fully realized the applicability. The multiple buildings as one building is a concept that I have only experienced theoretically in plan review, and have yet to see it applied here. Nevertheless, it is good to know. Thanks.

Have you ever used 3410.6.2 thru 3410.6.2.2 for calculating Allowable Building Area?

 

[alora]

503.1.2 Buildings on same lot. Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building if the height of each building and the aggregate area of buildings are within the limitations of Table 503 as modified by Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building.

Testing my reading comprehension, I wonder if brudgers is focusing on the highlighted sentence above.

"This code" is defined in 101.1.

 

[texasbo]

Testing my reading comprehension, I wonder if brudgers is focusing on the highlighted sentence above."This code" is defined in 101.1.

It would make more sense if he were. If he had just said the whole building had to comply with code requirements for a new building, he would have been closer to what the code says. "The provisions of this code applicable to the AGGREGATE building shall be applicable to EACH building".

Instead, he's saying that the new building has to meet all code provisions for a new buiilding, one of the existing buildings has to meet all provisions of a new building, and one of the existing buildings may have to comply with 34 or may have to meet all requirements of a new building, and that the new building and one existing building are an addition.

None of which are anywhere in the section you quoted, and shows a fundamental lack of ability to apply 503.1.2

34 has nothing to do whatsoever with this; again, "The provisions of this code applicable to the AGGREGATE building, shall be applicable to EACH building".

 

[alora]

It would make more sense if he were.Instead, he's saying that the new building has to meet all code provisions for a new buiilding, one of the existing buildings has to meet all provisions of a new building, and one of the existing buildings may have to comply with 34 or may have to meet all requirements of a new building, and that the new building and one existing building are an addition.

None of which area anywhere in the section you quoted, and shows a fundamental lack of ability to apply 503.1.2

3403.1 Existing buildings or structures. Additions or alterations to any building or structure shall comply with the requirements of the code for new construction. Additions or alterations shall not be made to an existing building or structure that will cause the existing building or structure to be in violation of any provisions of this code. An existing building plus additions shall comply with the height and area provisions of Chapter 5. Portions of the structure not altered and not affected by the alteration are not required to comply with the code requirements for a new structure.

You're right.

He referenced 3403.1 first.

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.

 

[texasbo]

You're right.He referenced 3403.1 first.

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.

The problem is that 503 doesn't consider this an "addition" or "alteration". It considers it one building. Nowhere in 503 does it mention addition or alteration. 503 doesn't care when the buildings were built. It just cares that there are multiple buildings being considered as a single building, and that all code provisions for that single building apply.

34 has nothing to do with this whatsoever.

 

[alora]

The problem is that 503 doesn't consider this an "addition" or "alteration". It considers it one building.

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

Couple that with

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

and I think I see that Chapters 5 & 34 are mutually applicable.