 It brings us to our very first question. To which doors does D221 apply? D221 operation of latch. It's 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, D221 applies to class 2 to 9 buildings. But we'll look through this question with an 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, 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. D221 app 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 to the side. It could be that we're landlocked either side and have to get our exits out the front. We've got this front door to reception, which is of interest. And the door leading into that is 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. The lunchroom offices, the open-plan office, sanitary compartments, which doors does D221 apply? Well, the doors subject to this provision are those. This is D221A. The doors subject to this provision are those which are in a required exit, secondly, forming part of a required exit, or in the path of travel to a required exit. We've got some defined terms which bring some meaning to these statements. The first is required. That's something which you need to meet a dean 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, 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 under exit there. It could be under AI, an internal or external stairway. Doesn't have to be fire-isolated. Just has to get you outside. 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 I4 there. 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 D111. 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 D221 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 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 a required exit, and therefore would be caught by D221. There's one other type of door that we mentioned earlier that's caught by D221, 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 of travel to a required exit, it's not defined, but it is just that. A path of travel is to a required exit is wherever you walk across on this floor plate to get into the exit. The exit, of course, being this fire-isolated passageway and steering combination. Note that the stair, this is the ground floor. There could be levels above which lead into the stair, but from anywhere on the floor plate, which isn't in an exit, if you have to, that contains your path of travel to get there. So it's gonna catch this door, isn't it? This is a door which is catching a lot of space. We've got our open-plane 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 D-221. But it also includes these ones. These are doors which are in 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 D-221A. D-221A sets the requirement and then we get our concession starting at B. And that includes B-1, so the Sanctuary Compartments. They don't need to have the D-221 compliance. There's a few others there, but I wanna draw our attention to B2D, a space which is otherwise inaccessible to persons at all times when the door is locked. Now, your boss's office, it could be said, 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. We're providing exception 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 B2D, we're trying to capture spaces which are unoccupied. It could be the cleaners room, it could be a small server room or a small store room. Places like that which are exempted, not the boss's office, because the boss is offered, 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 normally occupied. But when applying D221, 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 D221, but might have to comply with something like D3.1 which controls latch operation in the corns with 14, 28.1, 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 D221. I do want to point out the cleaners room, we're talking about a cleaners room which is a store room. I had a question in another city and basically it was said, put to me, don't you like cleaners? What's wrong with cleaners? You like your boss, but you don't like your cleaners. You're not letting them get out. No, no, if that was a cleaners lunch room, 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 D221B. I will open this up for discussion, but I do want to get started.