NCC Tutor lesson - Using the fire safety provisions in Volume Two

The focus of this video is on the specific fire safety provisions in the NCC Volume Two.

Transcript

[Voice over] Using the Fire Safety provisions in NCC Volume Two

NCC Tutor Series

The focus of this presentation is on the specific fire safety provisions in the NCC Volume Two.

This module is best viewed with a copy of the NCC on hand – to access the NCC, visit abcb.gov.au and register or log in to freely access it.

Slide 2

In this presentation you will learn:

Where fire safety is covered in NCC Volume Two.
Fire safety Performance Requirements in Part 2.3 and
Part 2.7.
Fire safety DTS Provisions in Part 3.7 and Part 3.10, and
The Assessment Methods and Verification Methods used in NCC Volume Two.

We will also explore some other useful resources.

Slide 3

Fire Safety in NCC Volume 2

There are two Performance Requirements in Part 2.3 of NCC Volume Two that reflect the key concerns for fire safety in the NCC:

The first is, Reducing the risk of a fire spreading between buildings or structures, and
The second is, Warning occupants in the event of a fire so that they can evacuate safely.

Protecting the building itself is not actually a primary aim of the NCC fire safety provisions. The building can burn down as long as the occupants can evacuate safely and the fire does not spread to other buildings.

The DTS Provisions in Part 3.7 also reflect these key concerns, with particular DTS Provisions that relate to the different factors that can affect the spread of fire from or to a building, and one that relates to warnings.

The four relevant Performance Requirements in Part 2.7 relate to:

Equipment or facilities installed in a building that can increase the risk of fire.
Buildings in alpine areas, with concerns being ensuring that exits are not blocked in snow conditions and ensuring that there is space for emergency vehicles.
Buildings in bushfire prone areas, that must meet additional standards to reflect the risk of bushfires, and
The construction of private bushfire shelters.

The DTS Provisions in Part 3.10 provide a means for complying with three of these four Performance Requirements.

There are no relevant DTS Provisions for P2.7.6 Private bushfire shelters, but there is a Verification Method in Part 2.7 that can be used. Verification Methods are discussed later in this presentation.

You should remember that you don’t have to use the DTS Provisions but can develop a Performance Solution instead. Or you can use a combination of a DTS Solutions a Performance Solutions.

Slide 5

Fire safety Performance Requirements in Part 2.3 of NCC Volume Two.

As we can see, we have two specific requirements; P2.3.1, relates to the spread of fire and P2.3.2 relates to automatic warning for occupants.

If we look at P2.3.1 Spread of Fire, we can see here that in a Class 1 building, it must be protected from fire, from another building other than the associated Class 10 building and the allotment boundary, other than the boundary adjoining the road or public space.

Let’s now look at some key elements. A Class 1 building only applies to a Class 1 building and not to the related Class 10 buildings. You may need to consider siting, materials, construction methods to reduce the risk from fire that will spread to or from a building or a boundary.

We need to also consider the associated Class 10 building. We want to protect the Class 1 building from fire from another Class 1 building on the same block, for example, a granny flat or sleep out. But this does not apply to the associated Class 10 buildings such as a garage, car port, shed or fence on the same property.

The allotment boundaries, the legal edge of the property may or may not have a fence or other clear delineation. We need to also consider that this applies, even if there's no buildings currently on the neighbouring properties.

When we look at figure 2.3.1, we can see the allotment boundary, the associated Class 10 buildings, and then other buildings other than associated Class 10. So we can see here in these dark line, the areas of potential fire spreading.

A Class 10a building is a private garage shed or a carport. And the key here is that we must not increase the fire risk to any nearby Class 2 to 9 buildings.

We also have a specific variation that applies in South Australia only.

A brush fence means a fence or gate that is primarily constructed of broom brush or Melaleuca Uncinata.

When we look at P 2.3.2 automatic warning for occupants, we can see here that in a Class 1 building occupants must be provided with an automatic warning on the detection of smoke, so that they may evacuate the building in the event of a fire, to a place of safety.

Let's look at a couple of key elements.

Once again, a Class 1 building is that this particular requirement only applies to Class 1 buildings and not Class 10 buildings or structures.

Tn relation to the automatic warning automatic means designed to operate when activated by heat smoke or fire sensing device. This is typically a smoke alarm, but this is not the only way of meeting this particular requirement.

Slide 6

What are the DTS Provisions in Part 3.7 Fire safety?

Part 3.7 Fire safety contains DTS Provisions for complying with the Performance Requirements of Part 2.3 Fire safety. They cover both Performance Requirements in Part 2.3, that is 2.3.1 Spread of fire and 2.3.2 Automatic warning for occupants.

Many of the provisions relate to the separation distances between buildings and structures and construction standards for situations in which these distances are not met, i.e. when the distance between buildings is less than the specified minimum distance.

There are also provisions relating to separating walls between sole occupancy units (SOUs), to ensure that they resist the spread of fire.

Part 3.7.1, fire properties for materials in construction - contains general concession for materials to be deemed non-combustible and can be used anywhere within Class 1 and Class 10 buildings.

It also contains requirements for fire hazard properties for sarking top materials used in a roof, flexible duct work used for the transfer of products initiating from a heat source that contains a flame.

Part 3.7.2 Fire separation of external walls talks about:

“encroachments” - An encroachment is something that advances “beyond the usual or proper limits”. In this case, it means parts of the building that extends within the required separation distance. Some building elements, such as gutters and eaves can extend within these limits, as long as they are built to the required fire safety standard.
It also talks about “appurtenant” structures - An appurtenance is defined as “something accessory to another and more important thing” (Macquarie Dictionary). So, a structure that is appurtenant to a building, is related to it in some way. In this Part, the term often refers to a garage that is associated with a house. A house might need to be protected from the spread of fire from an appurtenant structure such as a garage associated with the house, or from a non-appurtenant structure, such as a shed on a neighbouring property boundary.

Part 3.7.3 fire protection of separating walls and floors.

Fire protection for walls and floors that separate Class 1 buildings or separate a Class 1 building from an unrelated class 10a building, contains fire resistance levels, construction requirements, and protection of services in separating walls.

This section also contains fire protection for horizontal projections of floors, that form part of a separating wall as well as provisions for combustible roof lights in a roof required to have non-combustible covering.

In Part 3.7.4 fire separation of garage top dwellings,we have fire safety provisions where a Class 1a dwelling is located above a Class 10a private garage that is not associated with that dwelling.

There's requirements for the construction of walls that separate the class 1a dwelling. from the unrelated class 10a private garage, including FRL and material type, floors that separate the Class 1a dwelling from the unrelated Class 10a private garage.It's also worth seeing figure 3.7.4.1, separating wall and floor construction.

Part 3.7.5 Smoke alarms and evacuation lighting talks about:

Requirements for smoke alarms in Class 1a and Class 1b buildings, and.
The requirements for emergency lighting in Class 1b buildings.

When people are sleeping their sense of smell does not operate effectively, and they donot detect smoke. Part 3.7.5 also provides helpful explanatory information relating to smoke alarms.

When deciding on the position of smoke alarms it is important to remember that they are intended to detect smoke before it reaches the sleeping occupants of the building. This is to ensure that the occupants wake up and to allow time for the occupants to evacuate the building. Generally, this requires the smoke alarm to be located in a corridor between sleeping areas and living areas.

In a Class 1b building (such as a boarding house or short term accommodation), a lighting system must also be installed (and activated by the smoke alarms) to assist occupants to evacuate in the event of a fire. This is because the occupants are less likely to be familiar with the layout of the building and won’t necessarily be able to locate the exits easily in the case of a fire.

Figure 3.7.5.1 from NCC Volume Two illustrates an example of how smoke alarms should be located in a Class 1a building, where bedrooms are located in separate areas.

In figure 3.7.5.1 diagram c, this shows a Class 1b building where multiple rooms are served by a hallway and where smoke alarms should be located.

Slide 7

Let’s look at some questions to help understand how to interpret the DTS Provisions in Part 3.7.

Question 1: According to Part 3.7.1, what Australian Standard must flexible ductwork comply with, when it is used for the transfer of products initiating from a heat source that contains a flame?

Answer 1:

Part 3.7.1.2 Fire hazard properties
AS 4254.1 Ductwork for air-handling systems in buildings – Flexible duct

Question 2: According to Part 3.7.2, what distances are relevant when you are trying to determine whether an external wall of a Class 1 building requires fire-resisting construction?

Answer 2:

Part 3.7.2.2 External walls of Class 1 buildings.

They must comply with provisions of Part 3.7.2.4 (fire-resisting construction) if the wall is:

(a) 900 mm from an allotment boundary, other than the boundary adjoining a road or other public space, or

(b) 1.8 m from another building on the same allotment other than a Class 10 building associated with the Class 1 building or a detached part of the same Class 1 building.

Question 3: According to Part 3.7.2, what options do you have for the materials used in an external wall that must have a fire-resisting construction?

Answer 3:

Part 3.7.2.4 Construction of external walls, Clause (b).

An external wall that must be fire-resisting can be of:

Materials with an FRL of not less than 60/60/60 when tested from the outside, OR
Masonry-veneer construction in which the external masonry veneer is not less than 90 mm thick, OR
Masonry construction that is not less than 90 mm thick

Question 4: According to Part 3.7.3, what requirements apply to combustible roof lights that are installed in a roof or part of a roof that is required to have a non-combustible covering?

Answer 4:

Part 3.7.3.4 Roof lights.

The roof lights must:

Have an aggregate area not more than 20% of the roof or part of the roof, and
Be not less than 900 mm from the vertical projection of a separating wall extending to the underside of the roof covering

Question 5: According to Part 3.7.5, what Australian Standards apply to smoke alarms installed in Class 1 and Class 10 buildings, in different circumstances?

Answer 5:

Part 3.7.5.2 Smoke alarm requirements.

Smoke alarms must comply with:

AS 3786 Smoke alarms using scattered light, transmitted light or ionization, OR
AS 1670.1 Fire detection, warning, control and intercom systems – System design, installation and commissioning – Fire, when the smoke alarm is installed in a private garage where the use of the area is likely to result in spurious signals (provided that smoke alarms that comply with AS 3786 are installed elsewhere in the Class 1 building).

Slide 8

We will now investigate the four Verification Methods in Part 2.3.

Each Verification Method can be used to verify a part of the Performance Requirement P2.3.1, but not the entire requirement. Other means or Verification Methods are needed to fully comply with the requirement.

The Verification Methods given in this Part can be used for the purposes described, but do not have to be used. Other Verification Methods can also be used, subject to approval by the Approving Authority.

The Verification Methods can be used whether a DTS Solution or a Performance Solution is selected.

Slide 9

Let’s now look at some questions:

Which of the four verification methods in Part 2.3 could you use in each of the following circumstances?

Question 1: To verify compliance with requirements to avoid the spread of fire between buildings on adjoining allotments?

Answer 1:

V2.3.1.3 Avoidance of the spread of fire [P2.3.1(b)] (adjoining allotment).

Question 2: To verify compliance with requirements to avoid the spread of fire between buildings on the same allotment?

Answer 2:

V2.3.1.4 Avoidance of the spread of fire [P2.3.1(b)] (same allotment).

Question 3: To verify compliance with requirements to avoid the spread of fire from an allotment boundary?

Answer 3:

V2.3.1.2 Avoidance of the spread of fire [P2.3.1(a)(ii)].

Slide 10

Where would you place smoke alarms…

In the Class 1a building shown on the right, to comply with the DTS Provisions of Part 3.7.5 of NCC Volume Two?

Interconnected smoke alarms would be required in both hallways that lead to bedrooms.

Slide 11

Fire safety Performance Requirements in Part 2.7 of NCC Volume Two. Part P 2.7.3 heating appliances, contain specific requirements that apply to a heating appliance and its associated components within a building including an open fire place, chimney or the like.

When we look at the specific requirements, we can see here that it applies to the appliance itself and all associated components, such as duct work, piping, brackets, stands, and electrical components.

We can also see that there's some specific State and territory variations that apply particularly to Tasmania. The variation applies in Tasmania only, and that's a requirement to meet certain emissions limits.

In P 2.7.4 buildings in alpine areas, we've got further requirements.

When we look at some of the specific defined terms, the alpine areas define Schedule 3, Figure 1 alpine areas and Table 1 alpine areas with snow less significant.

Areas that received significant snow fall, which is likely to accumulate on the ground. These can create a risk for safe evacuation and emergency response. In particular that applies to New South Wales, Victoria and Tasmania.

The external trafficable structures relate to roads or lane ways, bridges or walkways, driveways, and balconies or decks with exits or fire stairways from the building.

When we look at C 1, obstruct a means of egress from any building to a road or open space, what we mean here, is where snow or ice may fall from the roof of a building that can actually restrict people's ability to enter or exit the building causing a problem for evacuation during an emergency.

Snow or ice from a building cannot fall onto other properties or road ways or public spaces or obstruct access from that building to any other building.

When we look at P 2.7.5 buildings in bushfire prone areas, we can see further specific requirements.

A designated bushfire prone area is land that is subject to, or likely to be subject to bushfires.

There's a New South Wales variation for this specific defined term. And that can be found in schedule one.

Bushfire prone areas are , legally designated by State and territory governments.

We can also see here that there's specific State and territory variations that applies to Tasmania.

It's adds the requirement to provide access for emergency vehicles and water supply for firefighting.

The last is P 2.7.6 private bush fire shelters.

We can see here that the private bushfire shelter must be designed and constructed to provide a tenable environment for occupants and so on.

When we explore what a tenable environment is, the shelter must provide an environment that is free of flame, heat, smoke and toxic gases for the number of people who might be expected to use it for as long as necessary.

How long depends on consideration of a number of specific factors that are listed here.

We can see that this only applies to Class 10c buildings, which are private bush shelters that is bushfire shelters associated with a private residential building, such as a Class 1 building.

We also have a specific note that there are no DTS provisions included in Volume 2 to this specific performance requirement.

We need to refer to the ABCB Performance Standard for Private Bushfire Shelters.

Slide 12

What are the DTS Provisions in Part 3.10 Ancillary provisions and additional construction requirements?

Part 3.10 Fire safety contains DTS Provisions for complying with the Performance Requirements of Part 2.7 Ancillary provisions and additional construction requirements.

They cover three of the fire safety related Performance Requirements in Part 2.7, that is:

2.7.3 Heating appliances
2.7.4 Buildings in alpine areas, and
2.7.5 Buildings in bushfire prone areas.

There are no DTS Provisions to meet the requirements of Performance Requirement 2.7.6 Private bushfire shelters. There is a Verification Method relevant to this Performance Requirement in Part 2.7. This is discussed later in Verification Methods.

Slide 13

We will now explore the three specific DTS provisions in Part 3.10.

We're going to look at 3.10.4, construction in alpine areas, 3.10.5 Construction in bushfire prone areas, and 3.10.7 boilers, pressure vessels, heating appliances, fireplaces, chimneys, and flues.

When we look at 3.10.4 construction in alpine areas, what we can see is there are some specific requirements.

External doorways must open in a way that is not impeded by snow and ice outside.

Trafficable structures serving the building must remain usable under snow conditions.

Snow and ice build up between and around buildings must be minimized and there must be provision of adequate clear space around the building for emergency vehicles and for other purposes. When we look at figure 3.10.4.3(c), clear spaces around buildings, embankments for adjoining buildings, we can see the specific distances required.

Here we're talking about a clear distance of not less than four meters, where there's an embankment of more than 900 millimetres.

When we look at figure 3.10.4.3(d) clear spaces around buildings, use of a threshold where clear space is not available, where we have an embankment of less than 900 millimetres, we can see in this example, clear distance is not specifically required to the door threshold.

When we look at 3.10.5 construction in bushfire prone areas, we can see the aim here is to reduce the risk of ignition in bushfire prone areas.

There are two specific acceptable construction manuals, AS 3959 Construction of buildings in bushfire prone areas or the Nash standard, which is a steel frame construction in a bushfire area. This applies to Class 1 and Class 10a buildings or decks associated with class 1 buildings in a bush fire prone area.

When we look at 3.10.7 boilers, pressure vessels, heating appliances, fireplaces, chimneys and flues, the acceptable construction manuals and the acceptable construction practices for the installation of heating appliances to comply with requirement P2.7.3, that covers open fireplaces, chimneys, insert fireplaces, flues, freestanding heating appliances, as well as boilers and pressure vessels.

Slide 12

Assessment Methods for fire safety in NCC Volume Two

Whether you choose to use a DTS Solution or a Performance Solution or a combination of the two, you may need to provide some evidence that the proposed solution complies with the Performance Requirements.

The NCC recognises four valid ways of assessing possible compliance solutions, which are shown here.

All four methods can be used to demonstrate compliance with all or part of the Performance Requirements when you are using a Performance Solution.

Evidence of suitability and Expert Judgement can be used when you are using a DTS Solution.

The various fire safety related Sections and Parts of NCC Volume Two include a number of relevant Verification Methods, each of which can be used in certain circumstances.

We will now look at each of the four assessment methods.

Verification methods is a performance solution.

There are four verification methods specified in Part 2.3 fire safety.

There are two verification methods in Part 2.7 and ancillary provisions and additional construction requirements. You can use another suitable verification method if it's been accepted by an appropriate authority.

The next is comparison with DTS provisions.

This is comparing a performance solution with the Deemed to Satisfy Provisions of the relevant parts.

The next is Evidence of Suitability.

This is meeting the prescriptive requirements of all the relevant DTS provisions of part 3.7 fire safety, and part 3.10 ancillary provisions and additional construction requirements.

The last is Expert Judgment.

This is where we use the expert judgment of a suitably qualified person. The expert must have demonstrated knowledge of technical issues and peer recognition.

For example, they might be a qualified and experienced fire safety engineer.

Slide 14

Here’s another example.

This time we will look at accommodation in Thredbo, NSW.

Like last time we need to consider a few additional things:

What classification applies to the different buildings?
What are the key fire safety risks for each building?
Which of the fire safety related Performance Requirements would apply to each building?
Where would fire resistant walls, floors or roofs be required?
Would smoke alarms or emergency lighting be required in these buildings?
Which DTS Provisions could be used to comply with the Performance Requirements?
How would you respond to other fire safety related requirements?
How would requirements change if these buildings were in a bushfire prone area?

The key considerations in this case would relate to:

The building being a Class 1b building.
Location is an alpine area, which means the provisions of P2.7.4 apply.
It’s possibly located in a bushfire prone area. In which case we need to check whether P2.7.5 also applies. To do so we would need to check NSW Government designation of bushfire-prone areas.
We also have an open fireplace in the lounge area which would require different construction to reduce the risk of the spread of flames, smoke and so on. The provisions of P2.7.3 would apply. DTS Provisions would include fire resistant construction underneath the fireplace and stove, and a flue above it, which would require appropriate construction to prevent the escape of flames, embers, heat, smoke or gases.
The boiler for heating water, supplying the radiators, which again would need a particular construction requirement, where we find P2.7.3 would apply.
We need to consider placement of smoke alarms, especially in the corridor which leads to four of the bedrooms and P2.3.2 would apply.
We would need to consider emergency lighting and where this might be placed.
And whilst there are no neighbouring buildings or roads that are shown here, we need to discuss the specific requirements for exit pathways ensuring there is appropriate clearance and space in particular for emergency vehicles.

Slide 15

There are also a number of useful resources we can examine.

There are explanatory videos from information sessions on the ABCB website. This includes information such as:

This is all non-mandatory and explanatory information only.

Standards are mandatory when referenced within the NCC’s DTS provisions or Performance Requirements. For example, if you decide to use the DTS provisions of Part 3.10 to comply with requirements for steel framed buildings in a bushfire prone area, then compliance with the NASH Standard would be mandatory. Alternatively AS 3959 Construction of buildings in bushfire prone area would apply. Remember that it is possible to use an alternative Performance Solution instead.

Handbooks and videos are non-mandatory resources that provide guidance and help, but nothing in them needs to be complied with in order to comply with the NCC. The ABCB Handbook, Bushfire Verification Method is an example of a non-mandatory resource.

Slide 16

The key points from this presentation are:

The overall aim for fire safety in Volume Two of the NCC is to:

Prevent the spread of fire from or to other buildings/structures.
Another aim is to warn occupants of a fire to allow for safe evacuation.

There are a number of key elements. The first is:

Avoiding the spread of fire between buildings. This relates largely to external walls.
The other is alerting occupants of a fire in a building. This mainly focusses on smoke alarms and emergency lighting).

Section 1 Governing Requirements must also be complied with.

Fire safety requirements can be met using DTS Provisions or a compliant Performance Solution.

There are also a number of Verification Methods.

Slide 17

This brings us to the end of this presentation.

Thank you for viewing this NCC Tutor module. Check out the other NCC Tutor modules available to build your understanding of the NCC.

[End of transcript]