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  • Overview: Heating and cooling load limits - NatHERS compliance pathway NCC 2019

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  • Overview: Heating and cooling load limits - NatHERS compliance pathway NCC 2019

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    The ABCB commissioned Strategy Policy Research to develop this Consultation Regulation Impact Statement (RIS), which accords with the requirements of Best Practice Regulation: A Guide for Ministerial Councils and National Standard Setting Bodies, as endorsed by the Council of Australian Governments in 2007. Its purpose is to inform interested parties and to assist the Australian Building Codes Board in its decision making on proposed amendments to the National Construction Code.

    The Australian Building Codes Board The Australian Building Codes Board (ABCB) is a joint initiative of all levels of government in Australia, together with the building industry. Its objective is to oversee issues relating to safety and health; amenity and accessibility, and sustainability in building. The ABCB promotes efficiency in the design, construction, performance and liveability of buildings through the National Construction Code (NCC), and the development of effective regulatory and non-regulatory approaches. The Board aims to establish effective and proportional codes, standards and regulatory systems that are consistent between States and Territories. For more information see the ABCB website (www.abcb.gov.au).

    Consultation This is a consultation document where interested parties are invited to provide comment on any matter raised in this RIS. A series of consultation questions have been provided, and respondents are encouraged to address these items to assist in the development of this document. Comments are invited using the ABCB RIS response form available from the Resource Library by close of business Friday 13 April 2018, and can be emailed to abcbris@abcb.gov.au with the subject title “Heating and Cooling Load limits”. The ABCB Office will review all comments received and incorporate stakeholder information and data into the regulatory analysis, as appropriate. The RIS will be revised in the light of stakeholder comments and will be forwarded to the Board as an input into its decision-making. The Consultation RIS can be downloaded from the ABCB website.

    http://www.abcb.gov.au/ http://abcb.gov.au/Resources/All-Resources mailto:abcbris@abcb.gov.au http://www.abcb.gov.au/Consultation/Regulation-Analysis/Consultation-RIS

  • Overview: Heating and cooling load limits - NatHERS compliance pathway NCC 2019

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    Copyright Copyright and licence notice

    © 2018 Commonwealth of Australia and States and Territories of Australia

    Ownership of intellectual property rights

    Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this publication is jointly owned by the Commonwealth, States and Territories of Australia.

    Creative Commons licence Attribution CC BY-NC-ND 4.0

    All material in this publication is licensed under a Creative Commons Attribution- NonCommercial-NoDerivatives 4.0 International Licence, save for logos. Attribution-NonCommercial-NoDerivatives 4.0 International Licence is a standard form licence agreement that does not permit any commercial use or derivatives of the original work. Under this licence: you may only distribute a verbatim copy of the work and must not adapt or change the work in any way. You must give appropriate credit and provide a link to the licence. You may do so in any reasonable manner, but not in any way that suggests the Commonwealth of Australia, States and Territories of Australia or Australian Building Codes Board endorses you or your use. You may not use the material for commercial purposes. If you remix, transform, or build upon the material for your own use, you may not distribute the modified material.

    The full licence terms are available from the Creative Commons website.

    Content contained herein should be attributed as:

    The Heating and Cooling Load Limits Consultation RIS© as released by the Australian Building Codes Board Office on behalf of the Commonwealth of Australia and States and Territories of Australia.


  • Overview: Heating and cooling load limits - NatHERS compliance pathway NCC 2019

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    1. Overview The purpose of this Section is to provide an overview of the proposed heating and cooling load limits for the Nationwide House Energy Rating Scheme (NatHERS) compliance pathway in the National Construction Code (NCC) 2019 Volumes One and Two. This section explains the need for heating and cooling load limits, how the load limits were developed, the outcomes and assumptions of the regulatory impact analysis for consultation. It also identifies a number of questions for feedback on the analysis. Responses to the questions at 5.1 will assist in the final decision Regulation Impact Statement.

    1.1 Why heating and cooling load limits are needed?

    The NCC requires building designs to appropriately utilise solar radiation, as determined by local climates and geographic features. The current Performance Requirement states that:

    “[A] building must have, to the degree necessary, a level of thermal performance to facilitate the efficient use of energy for artificial heating and cooling appropriate to—

    (e) solar radiation being—

    (i) utilised for heating; and

    (ii) controlled to minimise energy for cooling…”i

    These mandatory provisions require solar radiation to be well utilised, such as through appropriate orientation for necessary solar heat gain during winter, or by minimising cooling needs by reducing the absorption of solar radiation through the building fabric in summer.

    Rating of dwellings using house energy rating software, NatHERS, in NCC Volume One and Volume Two, is determined by the annual total energy load (i.e. a combined heating and cooling load). This may lead to a design that favours one side of energy use (either heating or cooling). A building can therefore meet the total energy load, but perform poorly in winter or summer.

    There have been a number of research papers/articles showing concern about this approach. For example, in climate zones with both heating and cooling needs, the cooling energy need can be exacerbated by a dwelling design that favours winter performanceii.

    Besides reducing energy use, introducing heating and cooling load limits may also result in health and social improvements. This includes decreasing peak energy load demand, lessening the pressure on the energy network, providing a more comfortable indoor environment year- round and assisting occupants (particularly those that are vulnerable) to cope with extreme weather.

  • 1.2 Current practice and research

    Having heating and cooling load limits is not a new concept. The New South Wales Government introduced heating and cooling caps under the Building Sustainability Index (BASIX) in 2004. The BASIX ‘thermal comfort’ element does not require dwellings to achieve a NatHERS star rating. Instead, BASIX requires compliance with individual heating and cooling caps unique to each climate zone.

    At the international level, the benefits of heating and cooling limits is also well acknowledged. In California, design heating and cooling loads must be met for a building, with specific rules applying for how to calculate heating and cooling loadsiii.

    In the European Union (EU), the ENTRANZE Project has involved wide-scale research on heating and cooling energy demand and loads for building types in EU countries. This project supports policy making on the transition to nearly zero energy buildings in the EU by 2020 for new buildingsiv.

    1.3 Policy context

    In 2016, the ABCB was requested to investigate having separate load limits as part of the energy efficiency project under Measure 31 of the National Energy Productivity Plan (NEPP). Funding was provided for this work through the Council of Australian Governments (COAG) Energy Council. This work was endorsed by the ABCB Board and included in the ABCB work plan. Introducing heating and cooling load limits, in addition to the existing star rating, for the NCC’s NatHERS compliance pathway is one of the key elements of the proposed energy efficiency changes for residential buildings in NCC 2019.

    2. How to determine heating and cooling load limits The focus of the energy efficiency changes for residential buildings in NCC 2019 is to improve the interpretation and application of the current provisions without increasing stringency. Thus the proposed heating and cooling load limits are not intended to change the overall stringency of NCC (i.e. the total energy load is to remain unchanged). The load limits will capture the worst performing dwellings with minimal effort to fix issues at the design stage.

    The ABCB engaged Tony Isaacs Consulting (TIC) and Energy Efficient Strategies (EES) to develop the heating and cooling load limits for the NatHERS compliance pathway.

    2.1 Scope of this work

    The proposed load limits cover the NatHERS compliance pathway as it appears in NCC 2016 (ignoring jurisdictional variations). In general, using the NatHERS compliance pathway, a Class 1 building must achieve a minimum 6 star rating. A minimum 5 star or 5.5 star rating is allowed in NCC climate zones 1 and 2 if the building has an outdoor liv