This video from the 2022 NCC Seminars discusses Schedule 1 Definitions from NCC 2022 Volume One.

Transcript

0:00

[Music]  

0:09

Hello, my name's Graham Moss I'm the Principal Building Surveyor for the Australian Building Codes Board.  

0:15

This video is a short update on changes to NCC  2022 in the definitions for BCA that's

0:22

Volumes One and Two of the NCC. So the first definition  change is how we've replaced average recurrence  

0:29

interval with annual exceedance probability. Now this change makes the BCA consistent with  

0:35

the AS 3500 series which uses the term annual  exceedance probability. Now average recurrence  

0:41

interval, average exceedance probability these  are actually two different ways of saying the  

0:44

same thing and that is the likelihood of a given  event occurring in any given year and of course  

0:50

for these defined terms it's the likelihood of a  given rainfall event occurring in any given year.  

0:56

The next definition changes the introduction of a  new defined term building complexity but before I  

1:02

show it to you I'm going to show you some trivia, the number of occurrences of defined terms in  

1:07

the BCA. So required I think is the most popular  defined term in the BCA it's got 1033 occurrences  

1:15

across both volumes. I was surprised by performance  solution I thought it wouldn't occur as often as  

1:21

it does but 620 times you see the defined term  performance solution used in BCA Volume One and Two.  

1:29

Now outdoor air I like this defined term I don't  know about you but I like defined terms I quite  

1:37

enjoy definitions possibly that's saying more  about me than it does about the definition for  

1:42

building complexity, however outdoor air  is not a very popular defined term it's  

1:47

used seven times in Volume One, four times  in Volume Two,only eleven times, so why is  

1:53

outdoor air one of my favorite definitions  well the definition for outdoor air is air  

1:59

outside the building. Now does that not appeal  to you it appeals to me I think it's amusing  

2:05

so that's why I was sad when I only found that  used 11 times in the BCA. So building complexity  

2:13

trivia for you how many times do we see the  words building complexity used in a defined sense  

2:18

in the Building Code of Australia for NCC 2022, zero. It makes outdoor air look popular doesn't it.

2:26

Now building complexity is a new concept included  in NCC 2022 it's a way of grading buildings by  

2:34

complexity but we don't use it in the BCA we  don't use it in the NCC entirely. Now why are we  

2:40

including it well it could be that we would use it  in the NCC in the future but also in the meantime  

2:45

it may be that state or territory legislation  would refer to this definition and require for  

2:50

instance that higher complexity buildings would  require further scrutiny, such as peer review.

2:56

So that's why we've included it despite not  using it now I'm going to show how building  

3:00

complexity works it works by the four criteria  that you see in the blue boxes on this slide  

3:06

we have attributes and that's where the  building exceeds 25 meters effective  

3:10

height or has performance solutions for fire or  structure or is in a place of natural hazard for  

3:15

instance the bushfire prone land. If you trigger  all of those or even just one of those attributes  

3:20

criteria then that's triggered that criteria  box and you have one criteria for complexity.

3:26

Next is Class 2, if your building is Class 2 then  that criteria applies, occupant number if you have  

3:32

more than 100 occupants in the building that's  also a criteria and fourthly occupant ability  

3:38

if more than 10 of those occupants require  evacuation assistance then you've triggered  

3:42

that criteria and of course as you go about  triggering criteria your score increases and  

3:48

you get a higher level of complexity, low for one  criteria, medium for two criteria you get the idea.

3:54

If all four criteria are triggered well that's  very high building complexity it's also the case  

4:00

that if your building is importance level 4 or  importance level 5, so of course we're talking  

4:04

about buildings essential for both disaster  operations like hospitals for instance. If you  

4:09

have an IL4 or IL5 building then of course that's  straight away a very high building complexity.

4:16

This next change is a new defined term for  volume and that applies for BCA Volume One.  

4:22

since its first edition the BCA has had  a definition for floor area but the BCA  

4:26

has never had a definition for volume. Now the  concept of volume is used a handful of times in  

4:32

BCA Volume One they're listed on this slide  here C3D3 for general floor area and volume  

4:37

limitations, C3D4 which uses the concept of  volume to describe a large isolated building,  

4:44

E1D8 for some Class 6 buildings of a certain  volume sprinklers are required and there's also  

4:50

smoke hazard provisions required in E2D10  for large isolated buildings again that concept  

4:56

of volume is used to describe a building for which  this smoke has a management provisions apply.  

5:02

Now sometimes at the ABCB office we've been receiving  calls where people say look I'm doing a volume  

5:09

calculation like for instance I'm trying to find  the maximum volume of my compartment and I've got  

5:13

this space in the building like in the photograph  here where there's all these trusses in the way no  

5:18

one's going to use that space so can I remove that  space for the purposes of calculating my volume. 

5:24

Well the answer that question is no because  that area is within the building within the fire 

5:28

compartment and therefore of course contributes  to the volume for the purposes of C3D3.

5:35

So what we've done for NCC 2022 is introduced this  new defined term volume in order to clarify that  

5:41

and other things, now it might look complex but  actually what we're doing with this defined term  

5:46

is taking the various scenarios for which the  concept of volume applies and setting up what  

5:50

the Deemed-to-Satisfy provisions require  to be contributing to the volume calculation.