Key Changes Proposed to the Energy Efficiency Provisions for Commercial Buildings in the NCC 2019
Changes to Energy & GHG Emission Savings are expected in the National Construction Code – NCC 2019
On December 2015, the Council of Australian Governments (COAG) published The National Energy Productivity Plan (NEPP) for the following 15 years,
The proposed changes, have both commercial and residential components.
Here are some useful links that will help you understand better the energy efficiency changes proposed for NCC 2019:
- Australian Building Codes Board (ABCB): Section J Overhaul – big changes are coming your way!
- National Energy Productivity Plan 2015-2030
- National Energy Productivity Plan Annual Report 2017
- Council of Australian Governments
HFM Asset Management & CADDS Energy Partnered to develop a Case Study on Part J of the NCC 2019
Along with our research partner CADDS Energy, we prepared one of a number of case studies, which helps explain the key changes proposed to Part J of the National Construction Code (NCC) 2019 Volume One and support the Public Comment Draft recently released.
Australian Building Codes Board have published our Case Study on their website and it can be downloaded here
The case studies, used computer modelling to analyse current examples of buildings designed to comply with Part J of the NCC 2016, against the proposed provisions of Part J of the 2019 NCC Volume One.
The purpose of the case studies was to uncover real evidence on the proposed changes and understand what a 2019 compliant building looks like.
When comparing our case study which used JV3 to comply with Part J NCC 2016, against a 2019 compliant DTS reference model the key take home messages where:
- Our case study was originally designed to be high performing and achieved compliance with the 2019 NCC without additional modifications / upgrades
- Clear benefit from the existing energy efficient design principles such as:
- High efficiency double glazing
- Solar passive orientation and design (e.g. shorter elevations on the east and west)
- Significant external shading
- Solar PV system
- There was a clear advantage in using performance solutions such as JV3 instead of prescriptive DTS requirements as it allowed:
- Significant external shading to be accounted for
- Trade-off of DTS non-compliant buildings elements (e.g. roof solar absorptance, minimum R-Value of the external walls and concrete slab above carpark) with a focus on weak spots (solar gains) resulting in overall envelope compliance thereby providing more flexibility in design and cost management.
Comparing the proposed Deemed to Satisfy (DTS) 2019 vs. the current DTS 2016 provisions of Part J we saw:
- Stringency increases aimed at reducing energy and GHG emissions
- Our modelling for a class 5 building showed a reduction in energy of 32% and greenhouse gas emissions of 37%
- Simplification of the Deemed to Satisfy (DTS) method:
- Moving away from the glazing calculator to a wall/glazing façade thermal calculation
- Consideration for the effects of thermal bridging on affecting overall R-Value.
- Expansion in compliance options to NABERS Commitment Agreement and Greenstar as verification methods will provide greater flexibility, reduce modelling requirements and documentation.
- HFM Asset Management supports the use of NABERS Commitment Agreement as a means of bridging the gap between design and operation.
- In many cases renewables (e.g. Solar PV) could be used under JV3 to mitigate / offset the increase in stringency provisions and achieve compliance
- Concerns around envelope requirements and compliance for smaller buildings – e.g. small end of town may face high costs for added stringency.
HFM wishes to acknowledge CADDS Energy for their assistance and the other presenters involved such as WSP, Team Catalyst and Arup who also provided excellent case studies and contributed greatly to the overall discussions.
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