"Within Dwelling Units"

[tomtomtom]

I try not to disparage building officials, but this is a new thread related to a previous one, discussing an issue where language is inadequate in code, and literal readings do not serves the spirit of the code:

The IBC provides numerous exceptions for R-2 and R-3 uses, I am unable to find interpretation describing the intent of "within dwelling units", which seemingly refers to that which serves a single residential unit, not which is within the envelope of that unit: Example, whether a egress stair that serves a single unit it inside the building, or outside the building.
Reasonable professionals and B.O. don't differentiate whether the component is enclosed, literal reading considers it inside the building.

Looking forward to something concrete... in lieu of IBC elaborating on this.

 

[bill1952]

I wondered if the entrance to the dwelling unit had to be at the foot (or head if dwelling was below) of the stair to be "within". An open to the public stair to your locked front door is not in the occupants control and is used by delivery people and others. I agree the existing wording needs clarification.

 

[Sifu]

I replied to the other thread with a review I conducted and to Bill's point, the entrance was at the foot of the stair, so no access to outsiders without a key, and enclosed by the rated demising walls and under-stair protection.

 

[tmurray]

Our code uses two different terms to differentiate the objective of the code and you used both in your post!

Within: Means physically inside. Ex: exit stairs within a single dwelling unit..., would mean stairs that are located inside the dwelling unit.
Serving: Means not necessarily inside, but are used by. Ex. exit stairs used to serving a single dwelling unit..., would mean a set of stairs who's only use is to access a single dwelling unit, but does not have to be inside the building.

With interpretation you need to not look just at what the code is saying, but also what it is not saying. You need to have a firm hand on all the code before you can really interpret one part of it.

 

[Yikes]

It seems like up to this point our discussion the exception "within a single dwelling unit" has been based on (a) occupant load, and (b) familiarity, to make travel on the stairs safer. Yes, a privacy gate at the bottom of the stairs would address both of these issues.

However, there has not been discussion of any other potential hazards related to the exterior nature of the stairs: rain, snow, ice, slippery leaf debris... none of which is mitigated by private vs. public.

 

[bill1952]

It seems like up to this point our discussion the exception "within a single dwelling unit" has been based on (a) occupant load, and (b) familiarity, to make travel on the stairs safer. Yes, a privacy gate at the bottom of the stairs would address both of these issues.

However, there has not been discussion of any other potential hazards related to the exterior nature of the stairs: rain, snow, ice, slippery leaf debris... none of which is mitigated by private vs. public.

True. I thought of that. But if the dwelling had a courtyard exposed to exterior completely surrounded by dwelling interior, isn't that the same? Or exterior stairs to a rooftop deck?

 

[Yikes]

True. I thought of that. But if the dwelling had a courtyard exposed to exterior completely surrounded by dwelling interior, isn't that the same? Or exterior stairs to a rooftop deck?

I feel weird here because I'm sounding a lot more conservative in my code interpretations than usual, but yes in that instance (the private fully enclosed courtyard) I would think the stair is no longer "within" the dwelling unit and would need 7" max riser, 11" min. tread.

If I were the O.P., I would take a different approach, the IEBC equivalent of "grandfathering", especially if there's no change in occupancy classification, arguing it's no less safe than before.

 

[bill1952]

I feel weird here because I'm sounding a lot more conservative in my code interpretations than usual, but yes in that instance (the private fully enclosed courtyard) I would think the stair is no longer "within" the dwelling unit and would need 7" max riser, 11" min. tread.

If I were the O.P., I would take a different approach, the IEBC equivalent of "grandfathering", especially if there's no change in occupancy classification, arguing it's no less safe than before.

Yikes - I agree with your reading of the code. Exterior stairs are not within a dwelling. Plain English. Not sure I think it is necessary for the intent of the code though, so maybe a change is required.

 

[Sifu]

It is problematic that the code language reads "in" an R3, and "within" an R2 dwelling unit. The difference makes it appear to be a purposeful distinction, which adds to my uncertainty in the context of the code. Both words could use some clarification IMHO.

 

[steveray]

The problem is if the terminology "serving" is used, it brings in common stairs, so the language would need to read more like "stairs used exclusively by occupants of the dwelling unit not for common or public use" OR we could just agree on the intent and play through...

 

[tbz]

The term "within" is specific to the interior conditioned space.

Section 1015. Guards was completely reviewed and re-written starting in 2004 through 2012 when the ICC board of directors established the Code Technology Committee and tasked them with working on Studying specific sections of code.

One such task was reviewing Climb ability of guard infill, "ladder effect".

During that process what came to focus was specifically the exterior balcony of an apartment or condo considered "within" the apartment, since no other unit has access to the balcony, except the "persons" living specifically in that unit. The determination was "NO" the balcony was not within the unit, but was exterior space.

Thus, the exterior balcony was required to have 42-inch high guards, not the relaxed 36 that was being discussed at the time during those multiple code changes from 2006 through 2012 editions.

I don't have copies of any commentary, but the intent when written into the code, by those submitting through the CTC proposals was noted in the monograph.

In the 2012 model IBC when I believe John W. and Dave C. got the under 3 stories with separate entrances exception added in, it again was specific to within for a reason of common areas on mixed use not being separated.

If the entrance is not from the public way to the front door without no other access by others, it is a common use stairway on the property with multiple use groups and subject to the more restrictive.

Though it might be vague in your mind, if you re-read 4 cycles on monographs and proposals from 2006 to 2015 you will find plenty of reference.

I am not seeing your point of beating a dead horse without explaining the heart ship of doing the normal minimum requirement.

 

[bill1952]

Interesting and useful but it should be in the law, not commentary.

 

[tbz]

Interesting and useful but it should be in the law, not commentary.

Bill,

I will use the argument of those that believe the model code does not need a definition of a landing, a landing is self-explanatory,

You are either within a structure or not within a structure. Hence, within is pretty much self-explanatory except for those searching for very deep and grey reasons not to do something, that is a minimum.

It would be nice to see someone argue why did they do it better than was needed, rather than a loophole for wanting to do something less than a minimum.

 

[bill1952]

You are either within a structure or not within a structure.

When you are in a stadium or outdoor performance space with parts covered and parts not covered, are you within it only to projected line of roof?

Still not sure an exterior stair that only serves a sf dwelling needs to be 7/11. Was that specifically addressed in the monographs?

 

[tbz]

When you are in a stadium or outdoor performance space with parts covered and parts not covered, are you within it only to projected line of roof?

Still not sure an exterior stair that only serves a sf dwelling needs to be 7/11. Was that specifically addressed in the monographs?

1.) I see your point, but the logic is still there you are within the structure or not-within the structure. The stair flight in questions is not within the structure by the OP's own acknowledgement.

2.) It was discussed every meeting when the committee's proposals were prepared for 3-code cycles, (2006, 2009 & 2012) in referenced to the guards, the language that was laterally attached to the stair flights during the discussions.

 

[tbz]

Of note bill, the OP has not responded to the simply question of why they feel the 7/11 is not warranted and is a "lot of stair".

My point is simple, I prefer a 12 on 6 riser when designing and building stair flights for residential homes, as thus the last exterior stair flight I worked on the cost difference from the adopted code of 8.25 on 9 IRC model to the 6 on 12 I preferred was less than $400.00, on a 10-foot elevation change outside.

I am trying to see what the issue is that is raising the question, if the area does not have enough room to get a 7/11 rise and run, tell us that.

I am having a hard time understanding the reason for the question other than they just don't want to do it.

I would even accept, well we built this stair already thinking it was fine and the AHJ failed it, I don't want to pay for another one.

Great reason to want to split hairs, and I would try the same thing.

However, the OP is questioning the wording "within" and that wording has been debated to death on the floors of code change hearings, and it always falls back on K.I.S.S., and based on that id does not support their reasoning in my book.

Convince me otherwise but giving me context, not theory.

 

[bill1952]

I did say above

Exterior stairs are not within a dwelling. Plain English.

so we agree. And when I have the say, I agree on 6/12 at least, 6/14 preferably stairs everywhere. I don't doubt it's been discussed. I miss the simple appendix of NFPA documents for ready reference. (FPN in NEC)

Your very practical

I am trying to see what the issue is that is raising the question, if the area does not have enough room to get a 7/11 rise and run, tell us that.

is very fair. I am purely a theorist on this, as interested in the quality of the writing as much as what is said.