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More NCC Changes Coming

The ABCB have recently released the proposed energy efficiency and condensation changes for the next edition of the National Construction Code (NCC) 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.  

Energy efficiency changes

The proposed NCC 2022 energy efficiency 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:

  • 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.

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).

Condensation changes

NCC 2019 introduced specific condensation management provisions 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:

  • changes to roof sarking installation, 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.

Want to know more?

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

HIA recently ran dedicated webinars on the energy efficiency and the condensation changes providing a detailed breakdown of the changes and these can be accessed at

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