To which doors does D2.21 apply?
2017 NCC Information Seminars
The 2017 NCC Information Seminars commenced with a presentation on ‘To which doors does D2.21 apply’ as part 1 of the 13 part BCA sessions delivered throughout February and March 2017.
This brings us to our very first question,
To which doors does D2.21 apply?
D2.21 operation of latch.
Since the provision, which is trying to prevent this sort of thing from happening.
The actual question that came to us came in for an office building, a Class 5 building.
But of course, D2.21 applies to Class 2 to 9 buildings.But we looked through this question with a office building in mind. -
Now the fellow who brought this question to us, he was sure that it applied to the actual exit, operation of latch.
You know the lever handle or the crash bar to the actual exit.
But he had a bit of confusion when applying it to other rooms and spaces in an office.
So that's what we're going to work through now.
D2.21 is the provision which ensures that certain latches are quickly and easily operated, and the intent is of course that we don't want evacuation to be slowed down by a door which is locked or hard to unlatch.
So we get that single downward action or the pushing action which leads to our lever or crash.
Here's a typical office layout.
We've got our fire isolated exit in the top left.
Fire isolated stair connected to a fire isolated passageway.
So in combination, these are an exit which lead down the side.It could be that we're landlocked either side and have to get our exits at the front.
We've got this front door to reception which is of interest.
This door leading into that, this corridor through the middle.
We've got this interesting door here.I've done a lot of work myself on secure government buildings and you get these corridor doors like this one, usually going from one security zone to another. -
So that one's of particular interest there when we're thinking about operation of latch.
We've also got various rooms off that corridor: lunchroom, offices, the open plan office, sanitary compartments.
To which doors does D2.21 apply?
The door subject to this provision are those, this is D2.21 (a)
The doors subject of this provision of those which are in a required exit.
Secondly, forming part of required exit or in the path of travel to a required exit.We've got some defined terms which brings some meaning to these statements.
The first is Required.
That's something which you need to meet Deemed-to-Satisfy or performance requirement.
The second defined term is Exit.
So note that Required and Exit isn't one defined term, they're two separate ones.
Required is something you need to meet the BCA.
Exit can be a number of things.
In fact, it could be something in isolation or combination.
Have a look at under Exit thereIt could be under a(i) an internal or external stairway.
It doesn't have to be fire isolated, it just has to get you outside.
It can include a ramp.
It doesn't have to be fire isolated either.
We have our fire isolated passageway, like in our example, and a door, so that's a (iv), a doorway opening to road or open space.We've also got the horizontal exit under (b)
Which is where like in hospitals, places like that, where you go from one fire compartment to another in accordance with D1.11
But note that an exit can include any of those things, either alone or in combination.
So, with that in mind, to which doors does D2.21 apply to?We're looking for doors in a required exit and we're also looking for doors which form part of a required exit.
That's these ones.
They're pretty easy to identify because they're all doors which have something to do with an exit.We've got the door leading into the fire isolated passageway which gets us straight into the exit there.
We've got a door in between the stair and the passage.That's a door in a required exit, isn't it?
We've got the door leading directly and outside, and our reception door here.
If it is a required exit, for instance, if we've got more than the distances specified in D1.4 from this particular exit into the fire isolated passageway and the reception door.That could be required to exit and therefore, would be caught by D2.21 -
There's one other type of door that we mentioned earlier that's caught by D2.21, and that's the door which is in the path of travel to a required exit.
Now this is the door which takes a bit of thought.
The first two are easy because they're directly associated with an exit.
But what's in the path of travel to a required exit? and path in travel to a required exit is not defined but it is just that.
A path of travel to a required exit is wherever you walk across on this floorplate to get into the exit.The exit, of course being this fire isolated passageway and stairing combination.
Note that the stair - this is the ground floor that could be levels above which lead into the stair.
But from anywhere on the floor plate which isn't in an exit, that contains your path to travel to get there.
So, that's going to catch this door, isn't it? This is a door which is catching a lot of space.
We've got our open plan office, some offices here could be our secure door,and it leads directly to this exit at the rear here.
Catching a lot of space.
It makes sense, doesn't it, that this door is in the path of travel to a required exit and therefore, would need to be easily operated in accordance with D2.21.
But it also includes these ones.These are doors between the path of travel to a required exit, simply where you need to walk through to get there.
There are a number of concessions or exemptions for D2.21 (a).
D2.21 (a) sets the requirement and then we get our concession starting at (b) and that includes b (i).
So the sanitary compartments, they don't need to have the D2.21 compliance.
There's a few others there but I want to draw our attention to (b)(ii) D
A space which is otherwise inaccessible to persons at all times when the door is locked.
Now your boss's office. Is that said to be a space which is inaccessible to persons when the door is locked?
so your boss goes out for lunch, locks the door behind him.
Is that a space which is inaccessible to persons when the door is locked?
Here's what we say in the guide.By providing exceptions to restricted access spaces and rooms otherwise inaccessible to people at all times, such as cleaners' rooms and the like.
So what we're trying to get at with (b) (ii) D, we're trying to capture spaces which are unoccupied.
It could be the cleaners' room, could be a small server room or a small storeroom.I think places like that which are could which are exempted, not the boss's office because the boss's office.
I don't know. My boss works hard.
He's in his office right now. It could be that your boss's office isn't normally occupied, but we're trying to capture those spaces which aren't aren't normally occupied.
But when applying D2.21 we must be aware that that's not the only provision which is about latch operation
It could be that you might have a door which is exempted from complying with D2.21 but might have to comply with something like D3.1 which controls latch operation in accordance with 1428.1 2009.
But to answer our question, except for the doors to the bathrooms, and also to the cleaners' room, all the doors here are subject to D2.21
I do want to point out that we're talking about a cleaners' room which is a storeroom.I had a question in another city and and basically, it was put to me.
Don't you like cleaners?
What's wrong with cleaners?
You like your boss but you don't like your cleaners as you're not letting them get out.
No. If that was a cleaners' lunchroom, certainly.
That's a space which is occupied and therefore, would need to comply.
But the cleaners' room, which is storing simply and not normally occupied enjoys the concession found in D2.21 (b)
I will open this up for discussion