Energy efficiency webinar – questions and answers

Each webinar provided information relating to that topic including:

• the key changes in NCC 2022
• the new mandatory requirements
• an overview of available compliance options
• when the changes will be adopted
• tips and examples
• how you can find more information and support.

You can access video recordings of the webinars on the ABCB YouTube channel.

Each webinar also provided the opportunity for attendees to ask questions about changes to NCC 2022. We could not provide answers to all questions asked during the webinar sessions, so this article provides answers to commonly asked questions from the energy efficiency webinars.

While we have endeavored to capture the intent of most questions asked during the webinar, there may be some that are not included in this article. This is likely due to the question being outside the scope of the NCC or not covered by the content in the energy efficiency webinars.

Do I need to install charging equipment for electric vehicles (EVs)?

No. The new Performance Requirement J1P4 Renewable energy and electric vehicle charging is to facilitate the future installation of charging equipment. The associated Deemed-to-Satisfy (DTS) Provisions in Part J9 of NCC Volume One are to ensure that electrical distribution boards are adequate, so future installation of charging equipment for EVs is feasible.

I understand 20% of the roof area of a building needs to be left clear for the potential future installation of photovoltaic (PV) panels under J9D5(2). Since not all PV panels have the same output, wouldn’t specifying a percentage of energy use be a more appropriate measure?

Since technology in this space is advancing quickly, roof area was chosen as the most practical measure for the future.

I read in Part B of NCC 2022 Volume One that Class 7b buildings (warehouses) need to allow for future structural loads from PV panels. Since J9D5(2) requires 20% of the roof area of any type of commercial building to be left clear for the potential future installation of PV panels, why don’t the additional structural load requirements for warehouses apply to all commercial buildings?

Part B contains additional structural load requirements for warehouses due to the large span steel roof designs typically used in these buildings. This means the structural effects of PV panel installation would likely be more pronounced in warehouses compared to other types of buildings.

For other building classifications, the Part B requirements are unchanged compared to NCC 2019 Amendment 1. This means the potential for future PV panel installation should be included in the structural assessment, just as it would have under previous versions of the NCC.

The person responsible for the design of the roof (likely the structural engineer) and other relevant stakeholders, should consider the likelihood of future PV panel installation for the building in question and design accordingly.

Is J1P4 Renewable energy and electric vehicle charging applicable only to new buildings and not to additions, and alterations?

The NCC requirements are usually applicable to new building works including all new works to an existing building in the form of alterations or additions. State and territory building regulations provide specific details on how the NCC requirements apply to the existing part of the building or the alterations and additions.

Is it necessary to comply with future installation of electric vehicles (EV) requirements (also known as the ‘EV readiness’ requirements) if the building doesn’t include any car parking facilities?

No. If a building does not include any carparks, then the NCC ‘EV readiness’ requirements do not apply.

Do the energy efficiency requirements for apartment  buildings as outlined in NCC 2022 apply to existing apartment buildings, particularly the EV readiness requirements?

No, the NCC does not apply retrospectively. Generally, it only applies to new building work, as described in each state and territory’s building regulations.

When determining the size of the switchboard to meet J9D5(1), how do I estimate the appropriate size of PV panels that may be installed in the future (for individual sole-occupancy units (SOUs), services and the entire building)?

When sizing your switchboard, you will have to use your judgement as to the potential future size of a solar system and the average efficiency of panels available etc. It is recommended, this should be determined in consultation with relevant stakeholders, such as the client/building owner. This will help determine the best outcome for your project.

I read in Part B of NCC 2022 Volume One that Class 7b buildings (warehouses) need to allow for future structural loads from PV panels. Since J9D5(2) requires 20% of the roof area of an apartment building to be left clear for the potential future installation of PV panels, why don’t the additional structural load requirements for warehouses apply to apartment buildings as well?

Part B contains additional structural load requirements for warehouses due to the large span steel roof designs typically used in these buildings. This means the structural effects of PV panel installation would likely be more pronounced in warehouses compared to other types of buildings.

For other building classifications, the Part B requirements are unchanged compared to NCC 2019 Amendment 1. This means the potential for future PV panel installation should be included in the structural assessment, just as it would have under previous versions of the NCC.

The person responsible for the design of the roof (likely the structural engineer) and other relevant stakeholders, should consider the likelihood of future PV panel installation for the building in question and design accordingly.

When complying with J1P3 Energy usage of a sole-occupancy unit for a class 2 building or a Class 4 part of a building, can Nationwide House Energy Rating Scheme (NatHERS) software be used if the apartment has a centralised hot water system?

No NatHERS software cannot be used if there is a centralised hot water system. There are no DTS compliance options for a Class 2 buildings with a centralised hot water system.

A Performance Solution, such as J1V5 Verification using a refence building for a Class 2 sole-occupancy unit, could be used for a proposed class 2 building with a centralised hot water system.

If I use a DTS Solution to meet Performance Requirements J1P2 Thermal performance of a sole-occupancy unit of a Class 2 building or a Class 4 part of a building and J1P3 Energy usage of a sole-occupancy unit for a class 2 building or a Class 4 part of a building for the SOUs of my apartment building, do I still need to provide NatHERS certificates in accordance with A5G9?

If you are using the NatHERS DTS pathway (J2D2(2)(a) and (3)(a)(ii), (b) and (c)), you must provide a NatHERS certificate (A5G9) as evidence. However, if you are using the DTS elemental pathway (J2D2(2)(b), (3)(a)(i), (b) and (c)) in Section J, a NatHERS certificate is not required.

It worth remembering that when using the NatHERS compliance option, there are still parts of Section J which still need to be met, such as Part J6 and J7 to meet Performance Requirements J1P2 and J1P3.

How do we decide which compliance option to use (i.e. NatHERS, elemental or Verification using a reference building) for our apartment building to demonstrate compliance with the relevant Performance Requirements?

This question is difficult to answer as it will vary greatly depending on the specifics of the individual apartment building in question. It is up to the collective experience of the design/compliance team to determine what compliance option to use based on all available information of the proposed building.

Do the new NCC housing energy efficiency requirements exclusively apply to new residences?

Generally, the NCC applies only to new building works, as defined in each state and territory’s building regulations. This includes new building works undertaken as alterations and additions. State and territory building regulations also outline if a trigger exists to upgrade the remainder of your existing building to the current NCC when undertaking an alteration or addition.

I’d like to install a swimming pool for my existing home. Do I need to demonstrate compliance with H6P2 Energy usage?

 

As with the previous question, generally the NCC only applies to new building works. You will have to check with your local jurisdiction, Building Surveyor/Certifier or appropriate authority to confirm how the NCC applies to a proposed swimming pool for an existing dwelling.

When undertaking a Whole-of-Home (WOH) assessment to meet H6P2 Energy usage, do I need to consider EVs?

No. When undertaking a WOH assessment, you only need to consider the domestic services, as defined in the NCC. These include heating and cooling equipment, heated water systems, swimming pool and spa pumps, and on-site renewable equipment such as PV panels.

When using H6V2 verification using a reference building, can I use a NatHERS software tool?

No. As stated in H6V2(1)(a), when developing a Performance Solution using H6V2, you must use a calculation method other than a software tool accredited or previously accredited under NatHERS including when run in non-regulatory mode.

When complying with H6P1 Thermal performance and H6P2 Energy usage, do I need to meet these individually or can I meet them collectively?

Your solution can meet H6P1 and H6P2 either collectively or individually, provided that all parts of each Performance Requirement are met.

A2G1 of all NCC Volumes specifies that all relevant NCC Performance Requirements need to be met to achieve compliance with the NCC. This means both H6P1 Thermal performance and H6P2 Energy usage need to be met in full for a dwelling, with no reduction or trading of performance between Performance Requirements permitted.

What tools have the ABCB published to support the new NCC 2022 housing energy efficiency requirements?

The ABCB have published finalised versions of the following calculators to support the new energy efficiency requirements:

• Whole-of-Home Calculator
• NCC Volume Two Glazing Calculator
• NCC Volume One Glazing Calculator (Class 2 and 4)
• NCC Volume One Lighting Calculator
• NCC Volume Two Lighting Calculator

Can I provide the NatHERS certificate even though I am not an accredited NatHERS assessor?

Yes. When using the NatHERS compliance option A5G9 states that a NatHERS certificate is required for evidence of suitability. The NCC does not require you to be an accredited assessor to provide a NatHERS certificate.

I’ve used a NatHERS thermal rating to meet H6P1 Thermal performance for my proposed house (for a sole-occupancy unit (SOU) refer J1P2 in Volume One). Do I need to use NatHERS software to meet the WOH requirements for H6P2 Energy use (for an SOU refer J1P3 in Volume One)?

No. If you have undertaken a thermal rating to meet H6P1 (or J1P2 for an SOU) using a NatHERS software tool, you do not have to use a NatHERS software tool to meet H6P2 (or J1P3 for an SOU). Instead, you could use another DTS option such as the elemental provisions. Refer to Part 13.6 of the Housing Provisions (or Part J3 for an SOU) for more information.

Remember, when using a NatHERS compliance option there are additional DTS Provisions in Part 13.7 of the Housing Provisions or Parts J6 and J7 in NCC Volume for an SOU which are also required for compliance with the NCC.

For more information on the availability of NatHERS software and training please visit NatHERS.gov.au.

If you want to know about energy efficiency in buildings watch the video recordings of the webinars here or download the Housing energy efficiency handbook.