This video from the 2022 NCC Seminars discusses Section D Access and Egress, and Section F Services and Equipment from NCC 2022 Volume One.
Hello my name is Graham, from the Australian Building Codes Board this video is an update on Sections D and E
access and egress and services and equipment of NCC 2022 Volume One.
First change to talk about today is in D2D3 number of exits known in 2019 as D1.2, now I've
got D1.2 on the screen here from 2019 because I want to show you something that we've changed for
2022. Notice that number of exits required for a Class 2 to 8 building over 25 meters
effective height that each story would need to have at least two exits and that makes
sense because tall buildings present evacuation difficulties. Now D1.2b has to be read alongside
subclause (g) and subclause (g) says that every occupant of a story, including the ground story,
in that 25 meter building needs to have access to at least two exits if two exits are required.
Now consider your typical hole in the wall cafe at the ground level of a building,
like the one pictured here, now if this building exceeded 25 meters effective height
then the cafe will not comply with D1.2 unless there's two exits, even if all the travel distances
required by D1.4 and other parts of the NCC are met because D1.2(g) is saying you have to, that
every occupant of that particular story including those in the cafe need to be able to get to at
least two exits without passing through another sole-occupancy unit. So for NCC 2022 we've updated
D2D3 to remove that requirement for the second exit for a part of a building like that cafe
which would otherwise meet the travel distance requirements of the BCA. Now on the screen we have
D2D3(2)(b) which applies for Class 2 to 8s there's also a similar exemption for Class 9 buildings in 4B.
The next change to show you is dimensions of exits and here on the screen we have BCA 2019
now you're probably aware that exits and paths of travels to exits need to be at least one meter
wide that's the D1.6(b)(i). Now you're probably also aware that in certain circumstances the BCA
allows a ladder to access a space so for instance consider a plant room less than 100 square meters
it's possible to use a ladder that complies with AS 1657 instead of a traditional step and riser
arrangement in accordance with BCA 2019 D2. Now those ladders are technically a path of travel to
an exit and ladders are typically less than one meter wide therefore for NCC 2022 we've included
this exemption in D2D8 which was D1.6 to include ladders. Now note that these ladders, this exemption
for ladders are only for ladders that are included for the reasons of D2D21, D3D23 and I3D5 that's
D2D21 for plant rooms the 100 square meter plant room concession I mentioned just now
D3D23 which is that provision that talks about allowing AS 1657 platforms and ladders for
service and storage areas and also of course I3D5 is the provision for farm buildings.
Now the reason we've actually specified that is the ladder must be provided in accordance
with these provisions or for the purposes of these provisions is that we don't want
people coming to site and finding that the exit path is less than one meter and think
okay here's the solution I'll put in a ladder no it doesn't work that way because the ladder must
be there for the reasons of those provisions not because there's a pinch point on site.
This next change is something new but at the same time it might look familiar to you
and that's because for NCC 2022 except for a standalone primary school that's no taller than
four stories every part of that primary school must be wholly within a story that provides
direct egress to road or open space this is a new Deemed-to-Satisfy requirement for NCC 2022.
If you want to do something different to that so for instance a five-story primary school or
a primary school in a mixed-use building where the primary school does not have direct egress
then you need to do a performance solution. As pointed out by the explanatory information on
this slide this is because of the difficulties associated with the evacuation of primary schools.
Now if this does sound familiar to you that's because you're thinking of D1.18 in NCC 2019, which
does similar things for early childhood centers. Now basically what we've done with this provision
is taken early childhood center and replace that with primary school, now we've done this because
for early childhood centers we've introduced additional Deemed-to-Satisfy provisions which
I'll show you in a moment,so that it's no longer necessary to do a performance solution for all
primary for all early childhood centers that exceed the parameters that are found in D1.18.
So what was the case for early childhood centers is now the case for certain primary schools
and those are these so consider building a building A is going to be a performance solution
it's all the same primary school it's a single-use building, however the building
exceeds four stories and therefore a performance solution is necessary it's not possible to
use the Deemed-to-Satisfy provisions of the building code as is the case under NCC 2019.
Now building B is within that four-story limit it's not a mixed use building and it's all the
same primary school so under D2D23 it's okay to use the existing Deemed-to-Satisfy provisions.
Consider building C, building C is also under four stories but it's a mixed-use building now
a mixed-use building does increase complexity for evacuation however the primary school is at the
ground level and therefore has direct egress, so under D2D23 you can use existing Deemed-to-Satisfy
provisions as is the case under 2019. But consider building D the primary school is in a
mixed-use building yet does not contain direct egress there's another use below it therefore
building D a performance solution would be required under these new provisions in NCC 2022.
This new provision D2D23 for primary schools
has some applications to go with it found in the application box
now this first application box is clarifying that when we're talking about a primary school of
course we're talking about kindergarten to year six which is what the Department of Education
calls a primary school but the application box is saying that when we're talking about a primary
school we're talking about parts of a school where it's reasonably expected to find students.
So the staff rooms you could find a primary school student in the staff
room you could find them in the classrooms of course, the offices, the canteen these
are all parts of a primary school where the vulnerable occupants can be found.
Now primary schools are very often found on the same campus or even in the same building as a
high school or an early learning center or other parts of a school which is still the same school
and that's why we have this second application.
What we're saying is that we have a primary school and a high school and it's all the same school and
it's all in the same building then there's no need to treat the building as a multi-use building for
egress because the whole building has the same occupant the evacuation problems that would be
found in a traditional mixed-use building aren't present. So the second application box says that
it's still a Deemed-to-Satisfy solution if you're less than four stories and the primary school is
part of a bigger school and note also this extends to the offices, it also extends to
a different classification a Class 7a car park where it's a car park for that particular school.
Now that's the new primary school provision which is requiring performance solutions for
large or difficult to egress primary schools. Now I mentioned earlier that what we'd had done is taken
early childhood centers out of D1.18 and replaced them with primary schools we're now going to cover
the changes or the additional Deemed-to-Satisfy provisions for early childhood centers. Now these
are all the provisions that have been amended to accommodate these new provisions. We're not going
to cover every amendment in detail but I do want to zoom in on this one A6G1, part of the governing
requirements, now note that this applies to all early childhood centers in mixed-use buildings.
This is the 10% concession you know the 10 rule where if you have multiple classifications in the
same story and one classification is less than 10 percent of the total area of the story then
you can apply the main classification the greater classification to the entire story.
Now for a long time that concession hasn't applied to laboratories or to
residential solo units this year as shown on this slide we've added early childhood centers.
Now the reason we've done this is because otherwise if you had a large building like
this Class 6 shopping center and the Class 9b early childhood center was this little part here
then that would be less than 10 percent and become a Class 6 shop instead of a
class 9b early childhood center and then would miss out on all these additional provisions.
Now you may be thinking that this hypothetical early childhood center that I've shown here is on
the ground floor has direct egress and therefore would not require the additional provisions now
for most of the provisions that is the case they don't apply, however sometimes they do. I'll show
you as we go through these provisions which ones do and which ones don't apply to early childhood
centers with direct egress, but first I'll show you how that's achieved and it's achieved by way of
these limitation boxes. So these limitation boxes are found when something won't apply to an early
childhood center that has direct egress or to an early childhood center that's a standalone center
of only two stories or up to two stories. So this is a particular example is found in
Specification 17 Clause 14, which is a new provision that requires quick response sprinklers for an
early childhood center that's at height. Now note how the limitation box removes that require for
quick response sprinklers to the early childhood centers that are low risk that have direct egress
and only a standalone story standalone center up to two stories rise in stories.
Note carefully that some of these new provisions do apply to early childhood centers like those
depicted on this diagram those that have direct egress or are only up to two stories in standalone.
I will point it out where they do though most of early childhood centers they're
at height that don't have direct egress, like this one for fire isolation.
If the early childhood center is in a mixed-use building it needs to be fire isolated from the
remainder of the building if you don't have direct egress as shown on the right the diagram on the
left the ECC the early childhood center has direct egress and therefore C3D6 does not apply there's
no necessity to fire isolate the early childhood center from the remainder of the building.
So next is compartmentation within the story itself so each story the center needs to be
separated into at least two fire compartments of course this applies only when we're at EEC's
that are at height, this won't apply to the single story direct egress or the double
story direct egress early childhood centers. Exits, so if you have an exit ramp it needs to
be fire isolated again this only applies to the early childhood centers that are found at height .
Also in Part D2 is horizontal exits where you have to divide your story into fire compartments each
compartment has to have at least two horizontal exits and of course those exits need to be at
least nine meters from one another and also nine meters from any other exit. You also have to be
able to fit the entire population of the story in either fire compartment you can see that
these provisions are about creating opportunity for staged evacuation getting the vulnerable
occupants away from the fire affected compartment which of course buys time for assisted evacuation.
Next in Part D3 we require appropriate handrails and balustrades you may be aware that in a primary
school we require additional kid-sized handrails for stairs and ramps to in addition to those that
are required for adult size, we've got kids size handrails. Well for NCC 2022 we now require toddler
sized handrails for early childhood centers. Now note carefully that there's no limitation box
on this new provision this applies across all early childhood centers, also I need to point
out for Part D3 that even though in the example on the screen here we have fire isolated exits
you'd be aware that fire isolated exits have a concession in the barrier for 300 sized openings
300 millimeters instead of 125 millimeter size openings well for an early childhood center that
concession is removed you must bring it down to 125 millimeter opening maximum because of
course we have little people using these exits and therefore we need to make them suitable.
Finally sprinkler protection now sprinklers aren't required in that standalone early
childhood center up to two stories in height or where we have direct egress, but in a mixed-use
building like the one shown on the right where the early childhood center does not have direct
egress then the whole building not just the early childhood center but the whole building needs
sprinkler protection and as I showed earlier the early childhood center needs quick response heads.
I just want to point one thing out about those quick response heads and I'll do that using the
examples shown on this slide. On the left here we have an early childhood center in a building that
exceeds 25 meters effective height so of course on account of exceeding 25 meters effective height
the building on the left requires sprinkler protection. Now the early childhood center
is receiving sprinklers in that building on the left not because it's an early childhood center
because as you can see the early childhood center has direct egress these additional requirements
don't apply. No, that early childhood center is receiving sprinklers because it's in a building
that exceeds 25 meters effective height, in that case standard heads are fine they're satisfactory.
Now consider the building on the right that building needs to be sprinkler protected
because it exceeds 25 meters effective height that's true but note the early childhood center
is found at height there is no direct egress and therefore that provision I showed
earlier applies and the early childhood center must have quick response heads.
Finally smoke detection now note that this one applies to all early childhood centers that is
for NCC 2022 smoke detection and alarm systems are required now in every building that contains an
early childhood center. Including those that enjoy direct egress, no limitation box found on this one.
so those are the changes for early childhood centers.
This next change is D3D16 currently known in NCC 2019 as D2.15, now for 2022 we've added the words
in resident use areas for Class 9c residential care buildings that's there in subclause (b).
I've shown you this definition on this screen we're talking about the residential areas of a building.
Now you'll notice that this matches subclause (a), which describes hospitals and how the patient care
areas for a Class 9a healthcare buildings are the only parts caught by subclause (a).
Now this is fixing a small problem that's currently in the code because currently you
can't have a step anywhere near the threshold of any doorway in the whole Class 9c building,
even the back door used only by staff where a step is going to be useful to stop the rain coming in.
Now in the current code subclause (b) overrides (d) which is the concession that allows that back
door to have a step. Now i'm told this is a common performance solution for
really what is an unintended oversight in the code so that's now fixed for NCC 2022.
This next change is to do with balustrade specifically face mounted balustrades and note
this changes found in Volumes One and Two. When I talk about a face mounted balustrade that might be
achieved by a spigot mount or it might be achieved like a bracket mount like in this photograph.
This is any configuration that's creating a gap between the edge of the traffickable surface
that's been protected and the balustrade, now some might say that under the current code that this
is this face mounted balustrate is okay so long as that gap doesn't allow a 125 millimeter sphere to
pass through, however a 125 millimeter gap is a big gap in that location and also I want to suggest to
you that if your barrier is set away from the side especially 125 millimeters away then it's
hard to say that your barrier is provided along the side of the traffickable surface which is
the current requirement shown here for BCA 2019 Volume Two, similar wording is found in Volume One.
However we do note that this is a popular balustrade design and therefore we've included
for both Volume One and Two this edition that is we're allowing face mounted barriers so
long as the gap measured horizontally doesn't exceed 40 millimeters. Now please do note that
this 40 millimeter allowance doesn't somehow stack with 125 millimeter provision that
exists today so you can't get a larger gap from that 125 it's still the case that the
125 sphere can't pass through any part of the barrier it's simply that we're permitting the
barrier to be located away from the edge so long as that awayness doesn't exceed 40 millimeters.