Energy efficiency and windows
Gary Smith explains how the requirement for energy efficient homes has seen an increase in window material and design innovation as well as discussing what further requirements will mean for the window industry moving forward.
The focus of Governments when it comes to energy efficiency are usually on the big ticket items such as carbon prices, international agreements and big industry. Since 2003 the flow through from these big ticket items to the building industry has been a focus on building more energy efficient homes to meet the requirements of the National Construction Code.
The impact on windows and doors from these requirements has seen an increase in higher performing products such as Insulated Glass Units, Low E glass, tinted glass, thermally broken aluminium frames, timber/aluminium composite frames and uPVC frames.
A new energy agreement signed in December 2015 by the federal, state and territory governments called the National Energy Productivity Plan (NEPP) was developed to provide guidance on the changes for energy efficiency in new and existing homes over the next few years.
There were three key actions identified in the NEPP focused on the housing industry they are:
- Action 5. Improve residential building rating and disclosure.
- Action 31. Advance the NCC.
- Action 32. Improve compliance with building energy efficiency regulation.
ACTION 5. IMPROVE RESIDENTIAL BUILDING RATING AND DISCLOSURE
This action opens the door to the introduction of mandatory disclosure at the point of sale or lease of existing homes, although it appears there may be more interest to start with a voluntary disclosure scheme, rather than a mandatory one.
The introduction of a disclosure scheme has been a recommendation in each energy policy statement since 2000 and the housing industry has expressed its support for this type of scheme for several years now.
The federal government has commenced research into a preferred scheme, picking up from where things left off in 2012 when a regulatory impact statement was released for a mandatory scheme. The Victorian government has been developing an online rating tool that is expected to be released at the end of 2016 as a voluntary option. While the New South Wales government is also undertaking research into how they could establish a tool.
The Window Energy Rating Scheme (WERS) performance data could be utilised in these tools and the AWA is working with government to enable this to occur.
ACTION 31. ADVANCE THE NCC
This action looks to increase the current six-star standard for new homes and new apartment buildings and recommends an increase in the requirements for commercial buildings.
Prior to the federal election, then Minister for Resources, Energy and Northern Australia, Josh Frydenberg, wrote to the Australian Building Codes Board (ABCB) requesting they commence investigation into the options to increase the stringency of the energy efficiency requirements for both commercial and residential buildings.
Minister Frydenberg has retained responsibility for the energy portfolio post-election although it has been shifted into the Department of Environment.
The Australian Building Codes Board has now commenced work on this recommendation, including establishing an ABCB Board steering committee, a Building Codes Committee working group and an industry technical reference group.
The ABCB has indicated that their intention for new homes is to investigate how to establish a new baseline for assessments which would use a ‘whole of house’ approach. Alongside this, the ABCB are looking at undertaking work to improve the drafting of the current code (Part 3.12) and potentially provide new verification methods to assist industry to meet the current six-star standard.
New South Wales currently uses a ‘whole of house’ approach under its BASIX rating tool. This option allows certain trade-offs and complementary actions to more accurately capture the energy used in a home, addressing fixed appliances and renewable energy options. There will always be minimum benchmarks for building fabric, so it is expected that the six-star rating would remain a minimum requirement of any new model. However, it would allow states such as Queensland and the Northern Territory to retain their tailored requirements and may create the opportunity for other states to offer this type of flexible approach.
While changes to the 2019 edition of the code are a possibility, it appears that the focus for residential buildings will be the 2022 edition of the code. Changes for commercial buildings standards will be the focus for 2019.
ACTION 32. IMPROVE COMPLIANCE WITH BUILDING ENERGY EFFICIENCY REGULATION
This action offers a way forward that would see government working with industry to improve what we deliver today, using today’s standards.
The Housing Industry Association has outlined a view that the ABCB, along with governments, should be focusing on providing support for the housing industry to better understand how to design and build six-star homes.
There needs to be better education to assist the industry to deliver six-star homes with a focus on training and information on insulation installation, building sealing and windows.
We see all too often the requirements for windows not met for some reason or another and this is only one component of the building.
As an example many energy ratings, particularly those entered into the free on line calculators are using glass only U Value and Solar Heat Gain Coefficient performance results.
Under the National Construction Code, energy efficiency provisions for Volume One, Section J2.4 Glazing and Volume Two, Section 22.214.171.124 External Glazing state that external glazing performance data must be determined in accordance with the guidelines of the AFRC (Australian Fenestration Rating Council).
By referring to glazing, J2.4 and section 126.96.36.199 require Total U-Values and Total SHGCs to be assessed for the combined effect of the glass and frame.
Energy ratings from AFRC accredited energy raters are the only acceptable performance results for use with:
- BCA Glazing Calculators (Volume 1 and 2),
- BASIX and
- NatHERS Software tools
Not using total window system values to Australian approved procedures and environmental conditions can result in significant under performance or over performance of the building envelope, especially in buildings with large glazed areas. The stated performance of the building will not meet the energy efficiency provisions of the BCA.
WHAT DOES THIS MEAN FOR THE WINDOW INDUSTRY?
In the short term, these recommendations are unlikely to change the requirements on energy efficient window systems. Over the medium term, with the renewed focus on energy efficiency, it is likely that there will be increases to the stringency on new buildings with the ABCB confirming increases to commercial building performance in 2019 and a likely increase to residential buildings in 2022.
Long term, this suggests that the performance of window systems will become more important to meet the overall requirements of energy efficient housing, with increasing stringency leading to the more common use of high performance products.
Kristen Brookfield, (December 2016). The Value of Energy. Windows, 16, 17.
Richard Hamber, (December 2016). The Value of Energy. Windows, 16, 17.
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