But wait there's more

In the words of the 1990s telemarketer Tim Shaw, when promoting the virtues of a knife set that can cut through a leather shoe – but wait, there’s more! And this time it’s not an additional set of leather shoe cutting knives for the one low price, but rather more proposed National Construction Code (NCC) 2022 changes are soon to be released for consultation. 

Recently HIA toured the country, presenting to more than 1000 people on the key proposed changes released for public comment in May. This included accessible housing proposals, weatherproofing and waterproofing changes, restructuring of the code, fire safety changes and much more. 

As if those changes weren’t daunting enough, the Australian Building Codes Board (ABCB) will soon release a further suite of proposed changes that will be just as significant as those previously released. 

So what will be released?

The ABCB has staged the consultation on NCC 2022 to assist the industry, given the scope and complexity of the proposed changes. In the spotlight for the changes being released in August for an eight-week consultation period are: 

• significant energy efficiency stringency increases 
• further measures aimed at addressing issues associated with condensation (moisture) management in buildings. 

These two topics are sure to garner substantial commentary about the suitability, effectiveness, costs, impacts on current materials, designs and construction methods as well as interaction with other aspects of the NCC and referenced standards. 

The Australian Building Codes Board (ABCB) will soon release a further suite of proposed changes that will be just as significant as those previously released. 

7 star and whole of house
In February 2019, the COAG Energy Council (state and territory energy ministers) agreed on a forward program for increases to the NCC energy-efficiency provisions over the next decade and beyond.
 
For Class 1 buildings and Class 2 buildings, the agreed trajectory recommends significant stringency increases for NCC 2022 and NCC 2025, and thereafter more gradual increases every three years until a target of zero energy (and carbon) ready buildings is achieved. 

The proposed NCC 2022 changes will include: 

For Class 1 buildings 
• Requiring the building fabric to achieve 7 stars 
• A significant rewrite of the DTS provisions of Part 3.12, set at a 7-star equivalence 
• Introducing new requirements for thermal bridging of steel framing 
• New whole of house provisions for determining the building services and potentially require solar PV panels for the building to offset the fixed appliances in the dwelling – likely to be a new ABCB calculator
• Revising the verification using reference building method 
• Developing a new quantified Performance Requirement (based on a societal cost of energy metric).
 
Concurrent work being undertaken on upgrading the star rating tools (AccuRate, FirstRate5, BERS Pro and HERO) to be set at 7 star and to be whole of house rating tools. 
Currently the star rating tools only assess the building fabric. 

For Class 2 buildings and Class 4 parts of a building 
• Using star-rating tools, the whole apartment building will need to achieve an average of 7-stars with no apartment permitted to be less than 6-stars (under NCC 2019 it is set at 6-star average and no apartment less than 5-star) 
• Developing new elemental DTS provisions for Class 2 buildings set at 7-star equivalence 
• Developing a new verification using reference building method for Class 2 buildings 
• Introducing new requirements for thermal bridging of steel framing 

Current state variations to the national energy efficiency provisions will be considered alongside the decision on the final NCC provisions, and there will be separate consultation on BASIX changes in NSW. 

Thermal bridging
A thermal bridge is any continuous path of conductive materials that crosses or ‘bridges’ the insulation in your walls and roof. This could be through the framing or any other elements that cross the insulation between the inside and outside of the building. 

‘Just like having a hole in your roof letting in the rain, excessive thermal bridging lets heat transfer between the interior and exterior of a building,’ explains Geoff Marsdon, executive general manager at Bondor Metecno Australia. ‘This reduces heating and cooling energy efficiency. The ABCB is considering addressing this through inclusion of thermal bridging within the NCC. 

‘One way to minimise thermal bridging is through use of structural insulated panels (SIPs) such as those provided by Bondor MetecnoPanel. These can be used to completely replace the insulated framing structure of your walls and roof, eliminating many thermal bridges,’ he says. 

‘One way to minimise thermal bridging is through use of structural insulated panel'

Breathing buildings
The issue of condensation in buildings and how the NCC should deal with the risk has been on the ABCB work program since 2014. The issue emerged in the colder climates of Australia but concerns have also been raised in warmer and humid climates. 

With the energy efficiency provisions in the NCC ramping up and buildings being more tightly sealed with less ability to breathe, condensation has become a real concern. 

NCC 2019 introduced requirements for vapour permeable membranes in certain climates, mandatory ducting and/or roof space ventilation and a new condensation risk management Verification Method. 

For NCC 2022 more substantive measures are being proposed including: 
• Reviewing the NCC 2019 provisions 
• Updating Australian Standards 
• Changes to wall sarking requirements to more vapour permeable type equivalent to Class 3 or Class 4 membrane 
• Ventilating roof spaces that include: 
– providing air spaces for roofs 
– changes to roof sarking installation for eaves and ridge 
– additional roof space ventilation via installation of whirlybirds, ridge or eave vents or similar. 
• Exhaust systems changes including: 
– Minimum flow rate for exhaust fans 
– Mandatory exhaust and ducting for rangehoods 
– No recirculating rangehoods permitted 
– Bathrooms not naturally ventilated have exhausts with 10-minute run-off timer.

Cost and impact assessment and how to find out more
In conjunction with the release of the energy efficiency and condensation proposed changes, the ABCB will release a range of consults reports on the various proposals broken down by the different climate zones as well as releasing a Consultation Regulatory Impact Statement looking at the costs and benefits of the changes.
 
Keep an eye out for further information from HIA on the release of these changes and HIA will be running a dedicated seminar/webinar breaking down the proposed changes and how they will impact houses and apartments in detail. To register for these sessions, go to www.hia.com.au