NCC Energy Efficiency and Condensation Changes

NCC 2022 Energy Efficiency and Condensation Changes Out for Comment

The proposed energy efficiency and condensation changes for the next edition of the National Construction Code (NCC) have been released for public comment and contain proposals that will have a major impact on the residential building industry.

If approved, these changes will affect all houses and apartments, increase construction costs and require changes to many standard building materials currently used. Many house and apartment designs will need to be changed to meet NCC 2022.

The release of these proposals follows consultation in July this year on the broader NCC 2022 proposed changes which were also substantial amendments.  

What are the major energy efficiency changes?

The proposed NCC 2022 changes include: 

For houses (Class 1 buildings)

All new houses will need to achieve an increased building fabric requirement of 7 stars – currently the building fabric is required to achieve 6 stars.

This will result in requiring higher windows and glazing performance, with increases in the required ceiling and wall insulation R-values. In some instances a 90mm wall frame will require a wall cavity to achieve compliance in addition to the higher insulation and wall wrap requirements.

The proposals will also see the need for changes to building designs and house layouts, restrictions on wall and roof colours in various climate zones and changes to structural floor systems (either insulated slabs or sub-floor insulation in most regions).

Other major changes include:    

• a significant rewrite of the DTS provisions of Part 3.12, to be at a 7-star equivalence,
• introducing new requirements for treating thermal bridging of steel framing including cavities, upgrading insulation or rigid board insulation to the wall frame,
• more stringent provisions for heating and air-conditioning systems and hot water systems,
• new whole of house energy budget provisions to determine the total energy use of fixed building services with recognition of potential offsets such as solar PV panels,
• revising the verification using reference building method including updates to achieve 7-star equivalence,
• developing a new quantified Performance Requirement for the new energy budget provisions (based on a societal cost of energy metric),
• upgrading of the star rating tools to incorporate a whole of house rating combined the thermal fabric (star rating) and the energy use budget requirements.

For apartments (Class 2 buildings)

The whole apartment building will need to achieve an average of 7-stars with no apartment permitted to be less than 6-stars (under NCC 2019 this is set at 6-star average and no apartment less than 5-stars).

The other major changes include:

• developing new elemental DTS provisions for Class 2 buildings set at 7-star equivalence (this will provide a second pathway for apartments to verify compliance after this option was removed in NCC 2010),
• developing a new verification using reference building method for Class 2 buildings, 
• introducing new requirements for thermal bridging of steel framing,
• new provisions designed for requiring ‘solar ready’ zones for potential future installation of on-site renewables and making provision for potential future installation of electric vehicle charging equipment for Class 2 to 9 buildings.

How about the condensation changes?

NCC 2019 introduced specific condensation management provision for the first time. For NCC 2022 more substantive measures are being proposed including:

• changes to wall sarking requirements to more vapour permeable types equivalent to Class 3 or Class 4 membrane, depending on the climate zone,
• ventilating roof spaces that includes: 
  • providing air spaces for roofs,
  • changes to roof sarking installation and roof sarking vapour permeability requirements, and
  • additional roof space ventilation via installation of whirlybirds, ridge or eave vents or similar.
• exhaust system changes including:
  • minimum flow rates for exhaust fans,
  • mandatory exhaust and ducting to the outside for rangehoods and exhaust fans,
  • banning recirculating rangehoods,
  • bathrooms not naturally ventilated must have exhaust fans with 10-minute run-off timer, and
  •  additional provision for ventilation to laundries/bathrooms containing a dryer.

How can you get a copy of the changes?

A copy of the draft NCC proposals and supporting documentation can be downloaded by visiting the ABCB Consultation Hub.

These changes affect both Volume One and Two of the NCC. There is also a range of reports, summary documents, case studies and supporting commentary documents to provide further detail on the changes.

Due to the code restructuring (released as part of stage 1 of the NCC 2022 public comment draft in July) the look and feel of the draft Volume Two (Housing Provisions) is quite different. Part 3.12 has been completely re-numbered. To help identify the proposed changes they are marked up in the draft code using green underline for new changes and red strikethrough for deletions.

What do you need to do?

HIA encourages all members to take time and review the changes. While you may not want to comment, it is important that you think about how your business will take on board the changes should they proceed next year.

If you do want to make comments on any changes you can do this directly to the ABCB by Sunday, October 17 2021. Comments must be submitted via the ABCB’s online Consultation Hub.

HIA is also keen to hear from members any views or concerns you have with the changes and you can share these by emailing our technical team.

Want to know more

HIA is running two dedicated webinars on the energy efficiency and the condensation changes. These webinars will provide members with a detailed breakdown of the impact the amendments will have on new home designs and construction techniques.

Members and other interested parties are encouraged to register for these sessions to find out more about the changes, how to provide comment and to prepare your business for these significant proposed changes.

You can register for the:

• Energy efficiency proposed changes webinar here

Condensation proposed changes webinar here