NCC 2022 Webinar Series: livable housing

Gary: G'day, welcome to this presentation on NCC 2022 covering livable housing design. My name is Gary Rake, and I'm your host for today.

Before we begin, I'd like to take a moment to say Yuma hello and acknowledge the Traditional Custodians of the land where we produced this presentation, the Ngunnawal people. I'd also like to acknowledge the Traditional Custodians of the land where you are viewing this presentation. I pay my respects to their Elders past and present.

Today's presenter is Alex Armstrong. Alex is one of our education team members at the Australian Building Codes Board. His work involves developing education and support materials for the code. After this session, the aim is that you'll have a better understanding of the relationship between the NCC and livable housing design and you'll learn the following; first, you'll be able to describe the changes to the National Construction Code 2022 as they relate to livable housing design. Next, you'll be able to interpret and understand some of those provisions and lastly, you'll be able to identify when these provisions will be adopted. Now I'll hand over to Alex, who will take you through the content.

Alex: Thank you, Gary. Here is the outline for today's webinar. I'll introduce the provisions and their intent and application. I will run through the DTS compliance pathway that includes the six parts of the ABCB Livable Housing Design Standard. I'll cover adoption dates and further information before we have some final questions. Okay, let's get started with our presentation.

The objective of the livable housing design requirements is to ensure that housing is designed to meet the needs of the community, including older people and those with mobility-related disabilities. The intent of livable housing design is to set out requirements that benefit all home occupants. This includes meeting the needs of people with reduced mobility. The requirements are a minimum standard and may not fully cover everyone's needs. There may be times where further design changes or home modifications are necessary to suit a person's specific needs or preferences.

The livable housing provisions apply to new houses and apartments through the Performance Requirements in NCC Volume One and Volume Two. The Deemed-to-Satisfy or DTS Provisions provide a compliance pathway to satisfy the Performance Requirements. Importantly for NCC 2022, there is a new referencing syntax Section-Part-Type-Clause across the code. It is referred to as SPTC. For example, in the diagram, the "P" in G7P1 and H8P1 means these are Performance Requirements, and similarly, the "D" in G7D1, G7D2, H8D1, and H8D2 means these are DTS provisions.

The livable housing requirements are in Part G7 of NCC Volume One and Part H8 of NCC Volume Two. These call up the ABCB Standard for livable housing design. The standard details technical provisions for DTS compliance for dwellings. This table [03:01 – 03:21] illustrates how the standard applies to apartments and dwellings. The NCC already has provisions for access to apartments in Part D4 of Volume One. Therefore, the dwelling access provisions of the standard do not apply to Class 2 apartments. All other parts of the standard ordinarily apply.

Let's take a closer look at the application of the standard to Class 2 apartments. G7D2 requires that all Class 2 sole occupancy units comply with Parts 2 to 6 of the Livable Housing Design Standard. These are shown by the blue lines on the diagram. As mentioned already, Part 1 of the standard, dwelling access, does not apply because Part D4 of NCC Volume One covers access to common areas and Class 2 buildings. That's indicated by the green lines on this diagram [03:22 – 03:47].

I'll now move on to the ABCB Livable Housing Design Standard. This provides the technical details for DTS solutions. Part 1 of the standard covers Dwelling Access. The intent of the Dwelling Access requirement is to provide safe and easy access from the allotment boundary or a designated parking space. Dwelling access is covered by the DTS provisions in NCC Volume Two. Clause H8D2(1) states that a Class 1a dwelling must comply with the standard.

Part 1 of the standard has two components: Step-free access path and parking space incorporated into step-free access path. Clause H8D2(2) provides exemptions for the requirement for a step-free access path. These exemptions include where there are steep sites, where there is ramping more than allowable gradient and/or length, and where there is insufficient space. I'll now cover these in more detail.

I'll start with the step-free access path, which is in Part 1 of the standard. The continuous step-free access path must be provided from the pedestrian entry at the allotment boundary or an appurtenant Class 10A garage, carport, or a carparking space provided for the exclusive use of the dwelling occupants. A continuous step-free entry from the allotment boundary to the dwelling entrance is suitable for many applications, including narrow lots, small sites, and sites with minimal setbacks. An example is shown. A step-free access path may also be provided from the appurtenant class 10A garage or carport. This option is suitable for many applications, including steep sites, large allotments, small sites, and minimal setbacks. In the scenario shown, the dwelling entrance from the garage must meet the dwelling entrance requirements of the standard. Another option is to provide a step-free access path from a carparking space, provided it is for the exclusive use by the dwelling occupants. This is suitable for many applications, including steep sites and large allotments. In the scenario shown, the requirements for a step-free path must be met from the parking space to the dwelling entrance. The step-free access path must; connect to the dwelling entrance door that complies with Part 2 for the standard for dwelling entrance, have no steps, be a minimum of 1000 millimeters wide, and have a crossfall no steeper than one in 40. Any gates on the access path must have a minimum clear opening width of 820 millimeters. The access path may also include ramps.

Let's now take a closer look at ramps and landings, as well as decks, verandas, and driveways used as part of the access path. Any ramps on the step-free access path must be a minimum of 1000 millimeters wide and have a gradient between one in 14 and one in 20. Ramps must also be provided with a minimum 1200 millimeter long landing at the top and bottom, with a crossfall no steeper than one in 40. A step-free path may also include one-step ramp. Landings are required at the end of each ramp, providing a safe transition between a sloped and level surface. The landing length must be a minimum of 1200 millimeters long and at least as wide as the ramp. Where a crossfall is provided for drainage, the crossfall must be one in 40 or shallower. Where ramping is provided by more than one slope, a landing needs to provide a safe transition. In this case, the landing is required to be a minimum 1200 millimeters long in each direction. For curved ramps, design guidance in Australian Standard 1428.1 may be considered. The standard permits the use of one-step ramps in an access path. A step ramp assists a person to ascend a small step, no more than 190 millimeters, but it cannot be longer than 1900 millimeters or steeper than one in 10. It's important to remember that there are other NCC requirements that apply to ramps when they are required for compliance with the Livable Housing Design Standard, for example, 11.2.4 of the Housing Provisions requires a slip-resistant finish to the ramp surface. For most outdoor ramps, this will mean a P5 or R12 finish.

Let's check in on how we are going with a quick knowledge check. True or false: As part of the DTS solution, a ramp landing can be outside the allotment boundary. The answer is false. The DTS provisions stipulate that the start of the access path is the allotment boundary, as stated in Clause 1.1(1)(a). Therefore, the use of the footpath to meet the ramping or landing requirements would require a performance solution.

Decks and verandas and other similar structures are a common attachment to Australian residential dwellings, where they form part of the access path to the entrance the requirements of the standard apply to these structures. Deck or boardwalk style paths need to comply with AS1684 or the Nash Center for residential and low-rise steel framing. The driveway can be a part of an access path if it complies with the requirements for access path gradients and length in the standard. If the gradient of a part or all of the driveway is one in 20 or steeper, it would be considered a ramp, and Clause 1.1(4) and (5) would apply in the same way as for a separate access path.

The second part of the dwelling access requirements covers situations where a parking space forms part of the access path. Clause 1.2 states that one or more parking spaces can form part of the required access path, provided that at least one parking space has an unobstructed size of at least 3200 millimeters wide by 5400 millimeters long and has a maximum gradient of one in 33 for bitumen or one in 40 for any other surface material. This clause applies to an appurtenant garage, carport, or parking space.

In this image, Option 1 shows an access path from the footpath, whereas Option 2 shows an access path shared with the parking space. You do not have to provide both the standard provides options, there is no need to specifically mark out the parking space. For example, a line marking, as there is no requirement for a parking space associated with a Class 1a dwelling to be marked out.

The key aim for designers of access paths is to come up with a practical and safe step-free path design that makes the path accessible for all people, regardless of their level of mobility. The design of the access path will be influenced by site topography, the location of the building on the site, and car parking requirements. You have flexibility in choosing the materials used to form the path, the main concern that is addressed by the standard is the materials and construction methods are fit for purpose.

A continuous access path needs to be clear of impediments to allow safe use. For example, avoiding objects that protrude onto the path, such as bench, posts, or letterbox. If ramps are used, care should be taken to minimize trip and fall hazards from raised edges.

We have covered Part 1 of H8D2 and the dwelling access requirements, the exemptions are provided in Part 2 of H8D2. These only apply for Class 1a buildings, this is because the step-free access requirements only apply to Class 1a buildings. I will now move on to the exemptions that may be applied. The exemptions have a prerequisite condition that a pertinent garage, carport, or parking space is not provided. An exemption may be applied if this prerequisite is met and if one or more of the following conditions are present. The area for the access path is too steep, ramping required would exceed gradient and/or length limits, and there is insufficient space.

Let's take a look at these conditions,  NCC Volume Two clause H8D2(2)a indicates that you cannot apply an exemption unless you can establish that step-free access is not provided from an appurtenant garage, carport, or carparking space. Some examples are, no garage, carport or parking space is proposed on the site. The garage, carport or parking space is on a different level to the rest of the dwelling and exclusive carparking is not provided. The exemption only applies to the ground where the access path would be constructed, not to the entire site, if the site has several possible locations where an access path could be constructed and at least one of these locations is one in 14 or less then the exemption would not apply.

This exemption is applied to the entire access path, not just the sections considered to be ramps. It’s purpose is to provide for situations where the amount of available space on a site is insufficient to accommodate a step-free access path. This may be due to the physical size of the site or regulations outside of the NCC which limit the proportion of a site that can be covered by structures and or impervious ground coverings. Remember these exemptions apply only to Part 1, so even if an exemption is applicable, all other relevant requirements of the standard must still be complied with.

There are other relevant NCC provisions for dwelling access, this includes the Performance Requirements in Volume Two H5P1 Movement to and within a building, this affects ramp and landings on the step-free access path, which will need to meet the DTS provisions for slip resistance in NCC Volume Two Clause H5D2 and the ABCB Housing Provision Standards Clauses 11.2.3, 11.2.4, and 11.2.5.

We'll now move on to the dwelling entrance provisions in part two of the standard. The intent of this requirement is for dwellings to be easy to enter and exit, including for older people and those with a mobility-related disability. The standard requires that at least one entry door into the dwelling needs to meet the requirements. This could be the front door or another door that connects to the step-free path, for example from the garage.

The dwelling entrance is covered by the following requirements: H8P1(b) and NCC Volume Two, and G7P1 in NCC Volume One. H8D2 in NCC Volume Two, and G7D2 and NCC Volume One, and Part 2 of the Standard.

There are four components for the dwelling entrance design and configuration covered in the standard. These are clear opening and width, threshold, landing area, and weatherproofing. We'll now go through each of these components in more detail.

The standard requires a clear opening width of 820 millimeters. This means 820 millimeters clear of the door leaf and frames. Generally, this means you'll need to use at least an 870 millimeter leaf door to achieve this. Assuming the depth of the doorstop is 11 millimeters on each side and the door depth is 35 millimeters , common industry standard, many door types may be used provided the overall clear opening width is not less than 820 millimeters. For example, double bifold and stacking sliding doors.

The standard provides options for complying with the threshold requirements for an entrance door. The first option is for a level threshold with a rebated door threshold seal. Another option is to have a door seal height that is no more than 5 millimeters with a rounded or beveled edge. The third option is to provide a ramp threshold maximum one in 8 gradient within the depth of the door jamb between the entry landing and the inside floor level.

The entrance door must have a clear space of at least 1200 millimeters by 1200 millimeters on the external side of the door with a gradient no steeper than one in 40. Access to this door must be unobstructed other than by a gate or screen door. However, Clause 2.3 does not apply to an entrance door that serves an appurtenant Class 10A garage or carport. This means that where the step-free access path is provided from the garage or carport, the 1200 millimeter by 1200 millimeter landing area is not required. A landing provided at one end of a ramp may also be counted as a landing for the purpose of the dwelling entrance requirements.

Clause 2.4 sets out several requirements for weatherproofing external step-free entrances. These include a channel drain that must be provided for the width of the entrance where the external surface of the entrance is considered impermeable. This channel drain also needs to meet the requirements of H2D2 drainage of Volume Two. The channel drain should be designed and constructed in a way to enable it to be inspected and cleaned. This will assist for the purpose of termite protection if required and keeping the drain clear in bushfire-prone areas.

Where the surface of the external entrance area is decking or another permeable surface, the drainage surface below also needs to meet the requirements Of H2D2 of Volume Two and AS3959 for designated bushfire-prone areas. At the dwelling entrance, a roof covering the landing area no smaller than 1200 millimeters by 1200 millimeters is required where the area is also provided with a fall away from the building shallower than one in 40. Note that any posts, columns, or other supports for the roof cover must not obstruct the minimum 1200 millimeter by 1200 millimeter space required for the landing area in front of the entry door, as per Clause 1.1(4).

There are other NCC provisions relevant to the dwelling entrances, including slip resistance and weatherproofing. Let's have a quick look at these provisions. If the dwelling entrance landing is shared with a ramp, it will need to meet the slip resistance and dimension requirements of NCC Volume Two H5D2, as detailed in the Housing Provisions Clauses 11.2.3, 11.2.4, and 11.2.5.

In NCC Volume Two H2P1 Rainwater management, includes Performance Requirements that cover surface water. Let's move on to the relevant DTS provisions for these Performance Requirements. The DTS provisions are found in NCC Volume Two Clause H2D2(b) Drainage. This includes requirements for the drainage of roofs in some areas where a drainage system is required, subsoil areas where excessive soil moisture problems may occur, and land adjoining or under buildings.

Clause H2D2 calls up Clause 3.3.3 of the ABCB Housing Provision Standard and contains an important limitation statement that excludes a landing area for the purpose of Clause 2.3 of the standard.

The next part of the standard covers internal doors and corridors. The intent of the requirements in Part 3 of the standard is to assist unimpeded movement within dwellings to improve their usability. Internal doors and corridors are covered by the following requirements: H8P1(c) and NCC Volume Two, G7P1 in NCC Volume One, H2D2 and NCC Volume Two, G7D2 and NCC Volume One, and Part 3 of the standard.

Clause 3.1 requires an internal doorway to have a minimum clear opening of 820 millimeters, regardless of the type of door used. The clear opening width is measured in the same way as the entrance door, clear of the door leaf and frames. Note that the door handles are allowed to encroach in this zone. Thresholds of internal doors must be level or have a height no more than five millimeters if the lip is rounded or beveled or be ramped within the depth of the door frame and have a gradient of no more than one in 8. The ramp also needs to be as wide as the door frame that it sits in.

A minimum clear width of 1000 millimeters is required for corridors always and the like if you're connected to a door that is subject to Clause 3.1. The clear width is measured between the finished wall surfaces, for example, plasterboard or Timber cladding. You do not take the measurement between the wall skirting boards or other wall moldings such as picture rails. Features such as power outlets, wall tiles, doorstops, and so on are also excluded. Dual hardware may encroach the minimum required corridor width. The requirement for corridor width does not apply to a stairway that is part of a path of travel to a shower compliant with Parts 5 and 6 on a level other than the entry level.

Let's look at part four of the standard. This covers sanitary compartments. Before I outline the provisions, I would like to clarify the term sanitary compartment. Sanitary compartment is an NCC defined term and means a room or space containing a closet pan or urinal. In this first figure, the room is a sanitary compartment because it contains the closet pan. In this figure, the room containing the baths is not a sanitary compartment as it does not contain a closet pan or urinal. Of course, the sanitary compartment is the room on the left.

The sanitary compartment requirements in Part 4 of the standard are intended to improve their accessibility and usability by occupants and visitors, including older people and those with a mobility-related disability. Part 4 specifies the minimum requirements for the design and construction of at least one sanitary compartment in a dwelling. To achieve this intent, sanitary compartments are covered by the following requirements: H8P1(d) in NCC Volume Two and G7P1 in NCC Volume One, H8D2 in NCC Volume Two and G7D2 in NCC Volume One, and Part 4 of the standard. Part 6 of the standard also applies, which we will cover shortly.

Clause 4.1 location requires at least one sanitary compartment to be located on the ground floor or entry level of a dwelling. Clear circulation space in front of and to the side of the toilet pan improves usability for children, older people, and people with a mobility disability. A sanitary compartment that is subject to Clause 4.1 needs to meet certain circulation requirements of the standard. The key requirement is a clear zone of 900 millimeters by 1200 millimeters immediately in front of the edge of the toilet pan. Skirting boards, architraves, toilet roll holders, door stops, etc., may encroach on the circulation space; however, the circulation space must be clear of the door swing. Where the toilet is located within opposing side walls, such as a separate compartment, there must be a minimum 900 millimeters between the finished wall surfaces. Where the toilet pan is within a combined bathroom space, as shown in this example, the side of the vanity or other obstruction such as the bath needs to be at least 400 millimeters from the center line of the toilet pan.

The standard also includes provisions for a shower. Part 5 of the standard seeks to ensure easy and independent access for all home occupants. Showers are covered by the requirements of H8P1(e) in NCC Volume Two and G7P1 in NCC Volume One, H8D2 in NCC Volume Two and G7D2 in NCC Volume One, and Part 5 of the standard. Part 6 of the standard also applies, which I'll cover shortly.

Regardless of the total number of showers in a dwelling, the standard requires that one shower needs to comply with the requirements of part 5. The compliant shower is not required to be on the ground or entry level.

Clause 5.2 of the standard requires at least one shower to have a hobless, step-free entry. This means the floor level within the shower recess must be level with the floor level outside of that recess, while still allowing for necessary falls to enable drainage of water to the recessed floor waste. A  5 millimeter high lip is permitted; this is commonly placed at the perimeter of the shower recess for water retention purposes. Other relevant provisions that apply to a shower include performance requirement H4P1 in NCC Volume Two, which covers requirements for wet areas in class 1A dwellings, and DTS Clause H4 D2, which states that compliance with AS3740 and part 10.2 of the Housing Provisions satisfies performance requirement H4 P1 for wet areas.

The last part of the standard covers the reinforcement of bathroom and sanitary compartment walls. The intent of these requirements is to ensure that certain walls adjacent to showers, toilets, and baths can support the future installation of grab rails. Reinforcements to walls are covered by the following requirements: H8P1(f) in NCC Volume Two and G7P1 in NCC Volume One, H8D2 in NCC Volume Two and G7D2 in NCC Volume One, and Part 6 of the standard.

All reinforcement is not required if the walls are constructed of concrete, masonry, or other material capable of supporting grab rails. This includes plaster applied to masonry or concrete. For walls not capable of supporting grab rails, reinforcement only applies to the sanitary compartments or bathrooms subject to requirements for Part 4 and Part 5.

Just to be clear, there is no requirement to install grab rails; only the blocking or sheeting to support them. Reinforcing must be constructed using a minimum 12 millimeter thick standard-grade plywood or similar, a minimum of 25 millimeter thick timber noggins. Noggin sizes are minimum; larger sizes are permitted. For example, offcuts from framing timber. Care is required when locating a cavity slider door in a wall requiring reinforcement adjacent to a fixture. This is to ensure the door operation is not impeded by future fixings. It is also important to ensure the frame can support sheeting linings and potential grab rails when being used. The noggins or sheeting can provide the wall reinforcement. In this image, the location of the noggin is shown. These are located at one side to the end of the bath and to an area alongside the length of the bath. If the sheeting is preferred, the required reinforcing location would look like this.

For shower areas, this image illustrates the location of noggins to two sides of the shower area. If the sheeting is preferred, the required reinforcing location would look like this. There are some instances where an exemption may apply. For showers and baths, reinforcing only needs to be provided for the available width of the wall. This includes where the available wall is narrower than the required reinforcing width or where a window encroaches in the reinforcement zone. This photo illustrates the concession. The window in the end wall encroaches most of the zone for the nogging or sheeting. It's not necessary to move the window to accommodate reinforcing, but it is necessary to provide reinforcing where the window does not encroach the reinforcement zone. The rear wall has no window, and reinforcing must be provided. A freestanding bath is excluded from the requirement to provide reinforcement because it does not have adjoining walls to which grab rails could be fixed.

The reinforcement provisions for toilet pans are slightly different. The main requirement is to provide sheeting to a wall adjacent to and within 460 millimeters of the center of the toilet pan. The required sheeting zone is shown in this image. But what happens if there is an encroachment to this zone? If there is an encroachment such as a windowsill, door, or the toilet center line is more than 460 millimeters from the wall, reinforcement must be provided behind the pan instead, as shown in these figures. The reinforcement may be noggins or sheeting.

That brings an end to discussing the livable housing technical requirements. So, we've now covered the main provisions of the standard. In addition to the standard, the ABCB also has other relevant publications on livable housing design. This includes the ABCB Handbook: Livable Housing Design. This handbook supports the standard with additional guidance and examples. There is also the ABCB Voluntary Standard: Beyond Minimum, which contains additional livable design features. Both of these publications are not mandatory.

Gary: Thanks for that, Alex. I hope everyone found that informative. That brings our presentation on the changes to livable housing design in NCC 2022 to a close. If you'd like more information, please visit abcb.gov.au. Thanks for watching.