NCC 2022 Webinar Series: apartment energy efficiency

Clare: Hi, and welcome to this presentation on our NCC 2022 Class 2 Apartment Energy Efficiency Provisions. I'm your host, Clare Wright.

Before we begin, let's take a moment to acknowledge the traditional owners of the lands on which we produce this presentation, the Ngunnawal peoples, and the traditional owners of the land from which you are watching this presentation. I'd like to pay my respects to their elders past and present and recognize their culture in the world.

Today's presenter is Mike Dodd. Mike is one of our energy efficiency team members here at the Australian Building Codes Board. His work involves project managing some of the energy efficiency changes included in the code.

Before we hand over to Mike, I'd like to cover off the learning outcomes for this presentation. After this session, the aim is that you'll have a better understanding of the NCC and learn the following.

First, be able to describe the changes to the National Construction Code as they relate to Class 2 apartment energy efficiency.

Second, interpret and understand some of these provisions.

And lastly, identify when these provisions will be adopted.

Now, I'll hand you over to Mike, who will take you through the content.

Mike: Today, I'll provide a summary of the recently released energy efficiency provisions included in the 2022 update of the NCC focusing on apartment buildings.

I'll start with an overview of the changes and their intent.

I'll cover the mandatory performance requirements and then look in detail at the different compliance options available.

I will also run through the new requirements for electric vehicles, or EVs, and renewable energy equipment that affect apartment buildings.

I will conclude by providing information on when the changes will be adopted and where further guidance can be found.

Okay, to begin with, I will cover the key changes that we think you need to be aware of.

There are four key things that I would like to highlight in relation to the energy efficiency changes for apartment buildings. I will go through each of these in more detail later, but here are the key changes.

Firstly, there are three new performance requirements, one related to the building fabric of apartments sole-occupancy units, one related to a unit's appliances, and one for apartment building common areas related to electric vehicle charging and renewable energy equipment.

Second, to help meet these new requirements, there are two new compliance pathways, a deemed-to-satisfy pathway and a verification method.

Third, there is a stringency increase for building fabric. This is equivalent to one star when using the NatHERS tool.

Finally, there are several new deemed-to-satisfy requirements for EV and renewable energy readiness. There are four objectives, which are to reduce energy consumption and energy peak demand, to reduce greenhouse gas emissions, to improve occupant health and amenity, and to make the retrofit of renewable energy and electric vehicle charging equipment easy.

The new requirements also help deliver on the commitment by all Australian governments to reduce greenhouse gas emissions. This includes the Australian government's enhanced 43% emissions reduction target for 2030 and commitment to net zero by 2050, which was announced in October, 2021.

I will now cover the mandatory performance requirements.

There are four mandatory energy efficiency performance requirements that relate to apartment buildings. One is existing, but updated. Three are new.

In this table [03:38 - 03:40], we can see which performance requirements apply to individual apartments and which apply to apartment buildings. J1P1 had a minor update for common areas. J1P2 is new and relates to building fabric. And J1P3 relates to energy usage.

The last new performance requirement is J1P4 and relates to EV charging and renewable energy equipment. I'll go through each in turn now. In 2019, JP1 was the only performance requirement in Section J and is retained in NCC 2022 as J1P1. The only change for 2022 is that it now explicitly excludes the sole-occupancy units of a Class 2 apartment building or a Class 4 part of a building. This is because they have their own dedicated performance requirements, which will come to in a minute.

But J1P1 still applies to the common areas of apartment buildings and other commercial building types. The extract on the screen [04:46 - 04:49] shows the update to this requirement. Only the highlighted words and the provision number has changed. You can see that most of this item is unchanged. This means it is business as usual for meeting this performance requirement for the common areas of Class 2 buildings.

Now, moving on to the new performance requirements, the first of the new performance requirements is J1P2, and it relates to the building fabric of the sole-occupancy unit. It mirrors performance requirement H6P1 for Class 1 buildings. Its objective is to ensure the fabric of a sole-occupancy unit mitigates the impact of hot and cold weather. This will allow heating and cooling equipment to run more efficiently and improve occupant health and amenity, including during blackouts.

The fabric of a sole-occupancy unit includes the external roof, floor, opaque walls, and glazing. The second new performance requirement relating to sole-occupancy units is J1P3. This requirement sets a maximum annual energy use budget that a residential building cannot exceed on a whole-of-home basis. This performance requirement mirrors the whole-of-home energy use requirement, H6P2, in Volume Two for houses. In an apartment unit, the whole-of-home energy budget allowance is bigger than for a detached house. This is because apartment dwellers usually face greater constraints on installing solar panels to offset their energy costs than people living in detached houses.

For both houses and apartments, the approach to meeting the energy use requirement is holistic. It's based on the total energy used by the regulated appliances, less any energy provided onsite by renewable energy, most likely solar. Regulated energy includes air conditioners, heated water systems, lighting and pools and spas. The intent is to ensure that the cost to run these appliances is reasonable for the people living there. However, it also considers the cost of greenhouse gas emissions and peak network demand. Benchmark efficiency levels for individual appliances are set for the annual energy use budget.

However, the holistic whole-of-home approach allows trading between the efficiency of different appliances or to trade off between appliance energy use and onsite renewable energy. The benchmark appliance efficiency levels include a three-star heat pump for space heating and cooling, a five-star instantaneous gas water heater, and a lighting power density of four watts per square metres. There's no allowance in the benchmark for pool and spa pumps, but as I've said, you do have to consider them when you are checking if you comply.

So an apartment unit with its own pool or spa will need to improve the efficiency of its cooling and heating appliances or install more solar to make up any gap. Cooking appliances and other appliances like computers and TVs aren't assessed.

We'll discuss compliance options later, but both NatHERS and elemental DTS pathways are available for J1P3, or you can verify using the reference building verification method. These provisions are supported through the expansion of NatHERS and also a new ABCB whole-of-home calculator.

The last new performance requirement relates to the common areas of apartments.

J1P4 is about the new EV charging readiness provisions that I will cover later, as well as provisions related to keeping roof zone free for solar PV. It requires features that facilitate the future installation of onsite renewable energy generation and storage and electric vehicle charging equipment.

Okay, now that the performance requirements have been covered, I'll go through the different options of demonstrating compliance, first for apartments and then for apartment common areas.

While the overall range of compliance options is broadly the same as for NCC 2019, there have been big changes in NCC 2022 to make the compliance options more accessible. This increases flexibility and aligns better with the approach taken for other building types like houses or commercial buildings.

There are three main compliance option changes that we will be looking at today. The first one is updates to the existing DTS energy rating pathway. The second is the new DTS elemental provisions. The third is the new J1V5 verification pathway, verification using a reference building, which provides a ready-made methodology for a performance solution for sole-occupancy units.

J1V4, verification of building envelope ceiling, can also be used to comply with the building ceiling requirements of J1P2. Of course, pure performance solutions are still available, but we won't be discussing that today. I would just note that the quantified performance requirements of J1P1, J1P2, and J1P3 do make it easier to develop a pure performance solution. More information on developing performance solutions is available on the ABCB website.

The first compliance option change we'll discuss is the NatHERS pathway. NatHERS is an energy rating tool. The NatHERS pathway is an existing compliance option, and practically speaking, the way it operates is broadly the same as under NCC 2019. However, the stringency has increased in NCC 2022, moving from an average of all apartments from six to seven stars and an increase from five to six stars for the minimum any one apartment can be. NatHERS has also now incorporates a whole-of-home rating tool that you can use when you are showing compliance with the energy usage performance requirement, J1P3. NatHERS whole-of-home provides a score out of 100 for an individual sole-occupancy unit, with the NCC requiring that each apartment achieve a score of not less than 50.

The NatHERS pathway by itself is not sufficient to show compliance with J1P3. You will still have to demonstrate elemental efficiency requirements for both air conditioning and ventilation, including equipment servicing the apartment and lighting. This can be done through parts J6 and J7, which were known as J5 and J6 in 2019. Apart from the numbering, they are unchanged from 2019. I won't cover this off further, but just to remind you that they exist, including the provisions for refrigerant pipework insulation and air conditioning control.

There are also some other changes to the NatHERS software, including that it now incorporates the impact of thermal bridging when determining the star rating. If you're interested, you can see the NCC 2022 and NatHERS Tools presentation for more information on that.

Also, note this and all our webinars will be available to view via the ABCB YouTube channel.

The next compliance option change we'll discuss is the DTS pathway for elemental provisions for sole-occupancy units, or SOUs.

In 2019, the NCC only included elemental provisions relating to the services and common areas of apartment buildings, but we now also have elemental provisions relating to sole-occupancy units.

J2D2 2 directs users to a range of other DTS clauses to satisfy performance requirement J1P2. These clauses relate to the thermal performance of the external building fabric.

The DTS provisions in J3D4 to J3D13 cover roofs, walls, floors, windows, and shadings.

For meeting J1P3, there are elemental provisions in J3D14 relating to the annual net energy usage of regulated appliances.

Existing provisions in parts J6 and J7 for air conditioning and lighting equipment also apply, as we've just mentioned. The elemental provisions cover both the fabric and appliances and are structured in a very similar way to those used for Class 1 dwellings. Also, many of the targets are similar because they are both set to align with a seven-star NatHERS performance.

There are some notable differences between Class 1A dwellings and Class 2 sole-occupancy units, which I'll cover on the next three slides.

Firstly, for apartment unit walls, the provision is expressed as a minimum total R-Value requirement. Whereas for houses, the requirement relates to the R-Value of added insulation. When you calculate the total R-Value of the apartment unit walls, you need to account for thermal bridging. There is also an option to show compliance of wall and window elements separately by applying J3D8, which covers walls, and J3D11 to J3D13, which covers glazing and shading. This is like the approach used in the DTS elemental provisions for houses. Alternatively, you can show compliance using the combined performance of walls and windows, either on a single facade or across four directions in J3D9.

This second option aligns with the approach used in the elemental provisions for commercial Class 3 to 9 buildings, where we look at the combined performance of the wall and window elements in the facade or across multiple facades. Just like with commercial buildings, this approach includes backstop total R-Values that the wall is required to achieve and solar absorption requirements.

The second area where you'll see notable differences between the elemental provisions for houses and apartments is in relation to floors. Elemental provisions for SOU floors are much simpler than for Class 1 houses. The provisions for apartment units focus on concrete floor slabs, since this is the most common type of construction. There are no provisions related to thermal bridging of apartment unit floors. This is because framed floors are far less likely to be used in apartment unit settings, and our thermal bridging provisions only deal with thermal bridging through the frame. Other building fabric elemental provisions, such as those dealing with roofs and window elements, are broadly similar to those in the housing provisions.

Now, I will go into the DTS requirements for J1P3, the energy usage requirement. As you will recall, the whole-of-home energy use budget is based on a benchmark package of appliances covering three-star space heating and cooling, five-star instantaneous gas, heated water, and four watts per square metre of lighting. J3D14 sets out the calculation to use to check if you comply. The calculation refers to the ABCB whole-of-home efficiency factors standard. This is available to download from the ABCB website. The calculation is based on the type of appliance selected, the appliance energy rating, the size and location of the sole-occupancy unit, and the capacity of onsite photovoltaics apportioned to the unit. And that's all. You don't need to consider the running hours or thermal loads, energy costs, or any other inputs. All of this is built into the standard, and it just works on the assumption that the dwelling achieved the seven-star NatHERS equivalent level for the fabric. The ABCB has also provided a simple-to-use whole-of-home calculator to assist in quickly determining if the requirement has been met.

I'll illustrate what this new whole-of-home requirement means in practice by running through a quick worked example using the calculator. This is what the calculator looks like. As you can see, it is relatively simple. The same calculator can be used for either a Class 1 dwelling or a Class 2 apartment. You don't need to include information on the thermal performance of the building fabric when using this calculator because the calculations assume that you got to the seven star or equivalent for the fabric.

The first thing to do is fill in the building information, including the state, climate zone, building classification and floor area. Note for floor area, use the total floor area of the dwelling. You should exclude any garage and common areas outside the unit, but should include a feature like a winter garden that is solely for the apartment unit. You'll see that using the information entered, the tool then calculates the net energy usage budget allowance for the apartment. This is the number we need to keep below. If an apartment unit is larger or in a hotter or colder climate, it naturally costs more to run, even with efficient appliances, so they would get a larger allowance than a smaller unit in a mild climate.

Now that we have a target, the next thing to do is enter the information about the main air conditioning system type, the heated water type, pool and spa types, and any solar PV if installed. We can then check that the target is not exceeded. In this example, we are assuming that there is a heat pump installed to heat and cool the living area, which we have designated as the main heating and cooling unit because we predict that it'll get the most use. The unit performs at a two-star level for cooling. So even if other air conditioning units are present in a bedroom or another space, we only need to enter the information for the main system. In this example, that same air conditioner also provides the main heating system but performs at a three to four and a half star for heating. Note, if the appliance was rated under the previous version of the GEMS scheme, that is before 2019, the ABCB whole-of-home efficiency factors standard gives guidance on how to convert the star rating.

We've then selected an instantaneous gas water heater and left the rest blank because there's no onsite PV, pool or spa for this building. With this information entered, we can see that this combination of appliances complies with the requirement, as indicated by the actual net energy usage cell turning green. In this example, the space cooling appliance is performing below the benchmark, but the space heating is performing above the benchmark. If this system did not comply, then some options to investigate would be increasing the efficiency of the heating, cooling or the water heater. And that's how the whole-of-home calculator works to determine the net equivalent energy usage.

At this point, I'd also like to cover off on how to approach apartments with shared or centralised systems for heating, cooling or heated water.

The J3D14 DTS clause is set at the apartment unit level. It is not intended to apply to centrally-provided services. Further, the input data used to develop the ABCB whole-of-home efficiency factors standard only considered small equipment of the type that would be used to service a sole-occupancy single unit. Whole-of-home efficiency factors should therefore not be used for centralised services.

So if you have a centralised air conditioning system, you may be better off using the verification method using a reference building, which we'll discuss shortly. But if you want to stick to a DTS elementals approach, then you can just refer to clause J1D6. This includes elemental provisions related to large space heating and cooling systems, often found in centralised services for apartment buildings. There are no DTS provisions for centralised water heating systems for domestic water applications. So if the apartment building has a centralised water heating system, you would need to use the verification method or a performance solution.

So that leads us to the last main compliance pathway for an apartment building. This option is found in J1V5 and is a verification method based on a reference building. Verification method J1V5 satisfies two performance requirements, J1P2 and J1P3. J1P2 sets heating and cooling load limits for a sole-occupancy unit. The verification method requires use of an energy stimulation package other than the NatHERS software to compare the heating and cooling loads of a proposed sole-occupancy unit against a reference sole-occupancy unit based on the deemed-to-satisfy provisions. J1P3 compliance can also be shown by using the same energy simulation to estimate the cost to run an apartment building's proposed appliance versus the benchmark set. The intent of J1V5 is to allow for a single energy model to cover all of the units in a Class 2 building. It can also be combined with J1V3 for a mixed use building or for common areas.

Of course, there are dedicated parameters and schedules for modeling input assumptions for SOUs, such as internal loads and occupancy profiles. They're set out in Specification 45. The J1V5 pathway for apartments shares a lot of similarities with J1V3, the pathway for commercial buildings, but importantly, it enables the energy model to show the benefits of natural ventilation in keeping an apartment comfortable. Modeling of natural ventilation is complex and may be outside the experience of energy simulators who have only worked on commercial buildings. This is because commercial buildings are usually fully mechanically air conditioned throughout the occupied spaces.

So ensure you understand how to properly account for natural ventilation, Using J1V5 as the pathway for J1P3 compliance when the apartments are served from central plant is straightforward. This is because the basis of comparison is on the annual total cost to run regulated energy using equipment across the building. Through the building energy simulations of the proposed and a reference building, you will build up a detailed model of the annual cost to run the appliances. Provided the model aligns with the requirements of Specification 45, if it is shown that the centralised system of the proposed building is cheaper to run than the benchmark appliances of the reference building, it should comply. Note that the cost here is societal costs. There is information in Specification 45 to help you calculate the societal cost based on the energy consumption, fuel type, time of use, and the state or territory where the building is located.

The pathways for apartment common areas to show compliance with J1P1 are largely unchanged since 2019, so it is essentially business as usual for the DTS and verification methods Green Star, J1V2 and verification using a reference building, J1V3.

However, there are a few changes that I should mention. This includes J1V1, the neighbours verification method now includes neighbours for apartment common areas, as well as other building types, like hotels and shopping centres. Previously, it was limited to office buildings only.

There have also been some changes to the DTS elemental provisions for slab-on-ground floors. Refer to the NCC 2022 commercial building presentation for details.

There are auto requirements to facilitate future installation of EV charging and onsite renewal generation, which I'll come to on the next slide.

Now let's move on to discussing the new suite of provisions designed to make it easy to retrofit solar panels, electric vehicle charging, and battery storage equipment into all buildings. These requirements will allow you to comply with the new J1P4 performance requirement.

To prepare for renewable energy technology, Section J has a range of new provisions for apartment buildings. There needs to be provisions for the future installation of EV chargers for 100% of car parks. Class 2 apartments, and almost all commercial buildings will also be required to install charge control devices that will ensure that electric vehicles will only be charged when there is available electrical capacity in the building. Without this requirement, apartment buildings would potentially need to double their electrical supply capacity to accommodate EV, so this helps to manage the capacity and demand impacts.

To accommodate the future installation of onsite renewables, there is provision for solar zones. The roof of apartment buildings and all commercial building types will be required to leave 20% of their roof free so that solar panels can easily be installed down the track.

Lastly, the provisions include that space is left on switchboards for the connection of future solar panels and batteries. It is worth noting that these provisions only require the allowance for this equipment to be installed. It does not require the installation of EV charging equipment at this point.

The DTS provision is J9D4. As mentioned previously, this clause is about EV readiness, not EV chargers. It's about laying the groundwork for easy EV charging installation later at a future cost.

To make the car park EV ready, there are three requirements related to physical infrastructure, electrical capacity and control equipment.

J9D4 is looking to facilitate provision of Type 2 EV chargers. These are the ones that can operate on a 32-amp circuit with readiness for AC charging, not DC charging.

For the first key requirement, physical infrastructure, we are mainly talking about distribution boards dedicated to EV charging. Clause J9D4 requires distribution boards to be placed in car parks at a differential rate, depending on the number of EV ready car parks per storey. This is the table that indicates how many distribution boards will be required. Basically, it's one per 24 EV-ready car park spaces. For Class 2 buildings, all the car park spaces need to be EV ready. For other building classes, the percentage of EV-ready parking spaces is lower.

The second key requirement relates to electrical capacity in distribution boards. This is dealt with in clause J9D4 2 B. What this is saying is that you need to size your EV circuits to be able to deliver 12 kilowatt hours of electricity through a charger in an eight-hour period. For Class 2 buildings, that eight-hour period is overnight.

The third key requirement relates to a charge control system with the ability to manage and control charging in response to minimum demand. At the very basic level, this could be achieved with timers in the distribution board and metering and breakers upstream. This will leave room for a smart system to be deployed over the top at a later date. The concept of load management is central to the measures. It keeps the costs to developers down by reducing or avoiding the need to upgrade the network connection.

We'll now look at the new provisions intended to allow for easy addition of solar voltaic or PV and batteries to Class 2 to 9 buildings. This is J9D5, facilities for solar voltaic and battery systems. There are exceptions for buildings that are small, heavily shaded, already have solar, or where most of the roof is used for other purposes, like a roof garden or car parking. There are two clauses in this provision.

Clause 1 relates to the building's main switchboard, and the second relates to the roof. To facilitate the future installation of solar PV on a building, you are required to leave at least one labelled circuit breaker slot on the main switchboard for a future use. This clause also requires the main switchboard to be sized to accommodate supply from a PV system that covers 20% of the roof space. There's also a requirement to leave at least one circuit breaker slot for a battery storage system.

The second clause sets out the requirement to leave 20% of the roof clear for ease of retrofit.

If you'd like to know more about what I have covered in this presentation, there are a few places you can visit.

The ABCB resource library has content to support you understanding your work. You can find the resource library on the ABCB website. Our resources include in-depth handbooks, helpful articles or calculators to provide further guidance when working with the NCC.

Alternatively, our YouTube channel has lots of helpful videos to watch at your own pace. If you are after more fundamental understanding of a topic, the NCC Tutor series of videos is a great introduction to different key components of the NCC.

Clare: Thanks for that, Mike. We hope everyone found that informative.

That brings our presentation on the changes to apartment energy efficiency in NCC 2022 to a close.

Again, if you want more information, visit abcb.gov.au.

Thanks for watching.