The Australian Building Codes Board (ABCB) has begun the process of reviewing energy efficiency provisions in the 2022 edition of the National Construction Code (NCC).
The ABCB has released a scoping study outlining a range of options for residential energy efficiency and commercial energy efficiency.
Initial feedback closed earlier this month with the study calling for a greater focus on ventilation issues.
“NCC 2022 should also consider changes to building sealing, ventilation, lighting, and split heating and cooling load limits, whilst ensuring there would be no adverse impacts on condensation and indoor air quality,” the study said.
“Industry-led analysis has identified benefits of improving building sealing and lighting.”
The issue is important because increasing building sealing was not considered in the Trajectory for Low Energy Homes project.
“However, NCC 2022 changes should consider increasing building sealing while managing ventilation issues more broadly, and consider opportunities to tighten split heating and cooling requirements,” the study said.
“Lighting changes should be considered from 2025, after the introduction of increased Minimum Energy Performance Standards for lighting from 2020.”
During the development of the NCC 2019 provisions for commercial buildings, the treatment of thermal bridging and Total R-Value calculations were noted for review.
With a stringency increase possible in NCC 2022, it now possible to review these requirements for residential buildings. Glazing was another area specifically identified for review given its significant impact on the energy efficiency of dwellings.
Impacts on condensation management will also be considered as part of the review of the building fabric and sealing provisions.
One proposal under consideration is minimum requirements for renewable energy for some residential and commercial buildings.
Minimum site requirements were recently introduced in California. Consideration will be given to whether similar requirements should be introduced for Australian residential buildings in 2022, with commercial buildings likely to follow in 2025.
It is also considered likely that many commercial buildings will voluntarily integrate on-site renewable energy into their design as it becomes an increasingly cost-effective pathway for meeting energy efficiency performance requirements.
“Given this, there is a role for the ABCB to investigate if there are any barriers within the NCC preventing the installation of on-site renewable energy systems, or if there is a role the NCC should play in assisting Australia’s energy grid cope with higher penetration of decentralised energy generation systems,” the scoping study said.
This investigation would include consideration of:
structural requirements that may need to change to accommodate roof mounted PV systems;
what minimum or maximum system sizes should be;
how energy storage systems should be treated; and
if there are building design features that should be added to facilitate the introduction of renewable energy at a later date (e.g. ensuring sufficient free space on roofs and sufficient capacity for electric vehicle charging)
Starring role for insulation
Australia’s residential building sector is large and growing.
The residential building sector is responsible for around 11 per cent of Australia’s emissions and 23 per cent of electricity use.
Australia has made important progress in residential building energy performance. New homes have improved considerably over the years, becoming more energy efficient. For example, in Victoria a sample of energy rated houses constructed prior to 1990 was found to have an average House Energy Rating of around 1.5 stars.
Following the introduction of insulation standards for new homes in 1991, homes constructed between 1990 and 2005 averaged around 3 stars. Today, new homes are required to meet the equivalent of 6 stars or greater in most states and territories.
Two decades of progress
Through the introduction of energy ratings and other energy performance standards, Australia has made considerable progress when it comes to efficiency and the transition to renewable energy.
For example, more than one in five Australian homes now have solar panels installed on the roof – the highest rate per capita in the world.
Appliances and equipment used within households have significantly improved too. Split system air conditioners are now 50 per cent more efficient than they were in 2001.
Around 27 per cent less energy is used by lighting since the phase out of inefficient lighting in 2009 and technological advances in LEDs.
The ABCB will now develop a work plan for the NCC 2022. A Consultation RIS will be released in the second half of next year as part of the ongoing review process.
A Decision RIS is scheduled for late 2021 with NCC 2022 provisions published in February, 2022.
NCC 2022 should come into effect May 1, 2022.