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NCC 2019 Energy Efficiency Requirements - What do these mean for Tasmania?

June 01, 2020

The National Construction Code (NCC) 2019 provisions contain wide reaching changes, this included to the energy efficiency provisions. Given the scope of the changes the ABCB provided industry with additional 12 month transition period for the energy efficiency changes to familiarise themselves with the changes.

However, the energy efficiency changes apply differently across the country and effect houses and apartments differently to commercial buildings.

So what do the changes mean for Tasmanian buildings?


For Class 1 buildings, NCC 2019 included changes to:

  • The verification using reference building method – V2.6.2.2, this included more prescriptive modelling requirements in using the method and explicitly stating that NatHERS software (Accurate, First Rate5 and BERS Pro) is not permitted to be used as part of applying the method.

    V2.6.2.2 is an optional method for demonstrating that building fabric and glazing meets NCC Performance Requirement P2.6.1 in lieu of using either 6 star or elemental DTS Provisions of Part 3.12.1 and 3.12.2.

  • Introduction of new optional blower door test method via a Verification Method – V2.6.2.3, that can be used in lieu of meeting the building sealing provisions of Part 3.12.3.
  • Minor changes to the building sealing provisions of Part 3.12.3, that made the provisions more prescriptive of types of seals used and when seals are required to be provided for doors and windows including new provisions of treating an internal access door between attached garage and the house.

Separate Heating and cooling loads assessment

There was additional provisions included for the assessment of additional heating and cooling load limits under a NatHERS assessment, i.e. meaning needing to meet a minimum 6 star standard and also assess separate heating and cooling load limits.

For Tasmania separate heating and cooling load limits are not required to be achieved. This is because some climates, such as Tasmania are dominated by cold weather (for purpose of the NCC Energy efficiency provisions), and as such the separate assessments of heating and cooling loads are not required for Tasmania.

You will note though that this is not specified in the NCC itself, rather through in NCC Volume Two (extract below), it refers users to the ABCB Standard for NatHERS Heating and Cooling Load Limits. Heating and cooling loads

(a) A building must achieve an energy rating, including the separate heating and cooling load limits, using house energy rating software, or greater than or equal to--

  1. 6 stars; or
  2. for a building in climate zones 1 or 2, 5.5 stars if the building has an outdoor living area as described in (c) if the outdoor living area--
    (A) is fully covered with an impervious roof having a Total R-Value greater than or equal to 1.5 (for downward heat flow); or
    (B) has a least one permanently installed ceiling fan; or
  3. for a building in climate zones 1 or 2, 5 stars if the buiding has an outdoor area as described in (c) if the outdoor living area--
    (A) is fully covered with an imperious roof having a Total R-Value greater than or equal to 1.5 (downward heat flow); and
    (B) has at least one permanently installed ceiling fan.

(b) The heating and cooling limits in (a) are specified in the ABCB Standard for NathHERS Heating and Cooling Load Limits.

In the Scope of the Standard it contains the following information to clarify the application of heating and cooling loads for Tasmania:

“1.2 Scope

This Standard provides details of the heating and cooling load limits that apply to the NatHERS compliance pathway in clause J0.2 of Volume One and clause of Volume Two of the NCC. It must be emphasised that this Standard is not a standalone requirement. These load limits are an additional requirement to the existing star ratings for Class 1 buildings, Class 2 sole-occupancy units (SOUs) and Class 4 parts of buildings.

Separate heating and cooling load limits are not required to be achieved in all 69 NatHERS climate zones. This is because some climates are dominated by hot or cold weather, such as the climate zones in the Northern Territory (NT), Tasmania (Tas) and some climates zones in Queensland (Qld) and Western Australia (WA). 

New South Wales (NSW) already has separate heating and cooling load limits (or “caps”) covered in its Building Sustainability Index (BASIX) Thermal Comfort requirements. 

Hence, heating and cooling load limits do not apply in NSW, NT, Tas and parts of Qld and WA.


For Class 2 buildings (apartments) the treatment for the fabric of the sole occupancy units remains as per NCC 2016 that average of 6 stars rating of apartments across the building with no unit less than 5 stars.

For apartments the NCC 2019 changes are similar to those for houses, although the verification using reference buildings is not applicable to Class 2 buildings.

In terms of the heating and cooling loads assessment for apartments in addition to meeting the star rating assessment, the additional assessment is not required for apartments in Tasmania for the same reasons they do not apply for houses.

In summary the changes for Class 2 buildings include-

  • Inclusion of the blower door test method (via an optional Verification Method JV3)
  • More prescriptive building sealing provisions in Part J3
  • Changes to Class 2 common area provisions
  • Building Services changes to:
    • Part J5 heating and air conditioning
    • Part J6 Lighting and power
    • Part J7 Heated water services and swimming pool and spa plant

    Commercial buildings:

    The changes to Section J for commercial buildings include:

    • Revised Section J Performance Requirement JP1 and removal of JP3
    • New Verification Method compliance options include GreenStar and NABERS
    • Substantially revised Section J DTS Provisions
    • Revised methodology for assessing combined facades including windows and cladding
    • New usage patterns for determining energy usage
    • Spandrel panels assessment
    • Thermal bridging requirements
    • Restrictions on certain roof colours
    • Substantially increases for heating and air-conditioning systems; and
    • New introduction of new façade calculator to replace the old glazing calculator.

    HIA have produced further information on the Section J Changes.

    Further information

    The ABCB have produced a range of new resources, YouTube videos, handbooks and new calculators to assist industry in applying the new provisions, and if you are supplying or specifying products, designing, building or approving commercial buildings then you are encouraged to review and familiarise yourself with these resources at

    HIA also recently ran a Section J webinar breaking down the changes and that can be accessed through the HIA website

    If you would like to discuss any of this information further contact HIA Building Services team on 1300 650 620 or email

    REF: BCA 20:31