Sweeping changes

There have three significant moments in time for Australia’s National Construction Code, formerly the Building Code of Australia (BCA). These were:

• 1988: the first edition of the consolidated Building Code of Australia (BCA) encompassing nationally consistent technical building requirements
  
• BCA 1996:
  
• The first edition of the BCA being a performance-based code offering both prescriptive Deemed-to-Satisfy Solutions and Performance (Alternative) Solutions to demonstrate compliance
• The full first edition of BCA Volume Two the ‘Housing Provisions’ providing a dedicated stand-alone code for houses, garages and other low-rise buildings and structures.
• 2011: the first edition of the National Construction Code encompassing both building and plumbing incorporating the Plumbing Code of Australia.

NCC 2022 will be the next and arguably the most significant amendment to the national building code since its inception. 

All in all NCC 2022 is shaping as the largest single amendments of any past amendments both in terms of the volume of changes and the scope and impact of the proposed reforms, particularly for houses and low-rise apartments. 

So what are the major reforms?

The proposed changes will significantly affect all residential buildings include:

• possible introduction of mandatory accessible housing provisions 
• increases in energy efficiency stringency
• new condensation provisions
• further changes to Acceptable Construction Practices (Volume Two ACPs)
  
• changes to waterproofing and weatherproofing
  
• further changes to fire safety provisions in high-rise buildings
  
• enhanced building product documentation requirements
  
• new lead in plumbing products standards
  
• re-structuring of NCC Volume Two and re-numbering of all NCC clauses
  
• implementing relevant NCC changes resulting from the Shergold/Weir Building Confidence Report (building product changes and complex buildings).

Accessible, adaptable, livable, universal homes

In July last year, the Australian Building Codes Board (ABCB) released a Regulation Impact Statement (RIS) on potential mandatory accessible housing provisions in the building code.

The Consultation RIS reviewed six potential approaches, four being code amendments and two being alternative non-regulatory options aimed at increasing voluntary uptake by home owners.

• Option 1 – Adopting the Silver Livable Housing Design Guidelines (LHDG) features for all houses and apartments.
  
• Option 2 – Adopting the Gold LHDG design features for all houses and apartments.
  
• Option 3 – Adopting a combination of LHDG design features for all houses and apartments.
  
• Option 4 – Adopting the Gold LHDG design features for apartments only.
  
• Option 5 – Taking an enhanced approach to the voluntary adoption of inclusions by incorporating direct subsidies for households requiring tailored support.
  
• Option 6 – Publishing the LHD Guidelines as a voluntary ABCB handbook, creating a real estate match making service for households in need and including information on livable housing features in point of sale information (a type of disclosure scheme).

Building ministers are currently settling a position on the inclusion of minimum accessibility standards in the NCC 2022 public comment draft at their 30 April meeting, following consideration of the Final RIS by State, Territory and Federal Cabinets.
A potential outcome of Ministers’ consideration is the inclusion of draft proposals based on Silver Livable Housing Design Guidelines features.

This would require all houses and apartments to include:

• Step free path from boundary to front door, including prescribed path and ramping requirements
  
• Step free threshold to entrance door, minimum door way width (870mm door required) and 1.2 x 1.2 landing at entrance door
  
• Minimum 1-metre-wide hallways and passages
  
• Minimum door way width (870mm door required) for doors on ground floor
  
• Toilet on ground floor and circulation spaces in front of pan to door swing
  
• Step free and hobless shower with removable screen
  
• Reinforcing of walls surrounding toilet, bath and shower to allow for future installation of grabrails.

The provisions allow some concessions from the step free entrance path due to certain site conditions – for example, insufficient ramping space or grade of site greater than 1 in 14, and permits as an alternate to step free entrance that the entrance be through an attached garage.

If these are supported, it would result in significant changes to most house and apartment designs, additional excavations and/or cut and fill for sites and for a number of standard building materials used such as entrance and internal doors.

Whole of house approach to energy efficiency

In February 2019 the COAG Energy Council (State and Territory Energy Ministers) met and 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 includes:

For Class 1 buildings

• Requiring the building fabric to be set at 7 stars
  
• A significant re-write 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 required size of PV required for the building – 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).

The concurrent work being undertaking on upgrading the star rating tools (Accurate, first rate5, 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. They are also likely to be expanded to include other rating tools including BASIX in NSW and potentially the Net Zero Carbon tool recently developed in Victoria.

For Class 2 buildings and Class 4 parts of a building

• Under star rating approach, it will require 7-star average approach across the apartment building 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.

Given the scope of these changes and their complex nature, they will be released for consultation separate to the remainder of the NCC in mid-July for an eight-week consultation period. The condensation provisions will also be released for consultation at this time. 

HIA will convene some workshops in late July to further discuss and break down these changes.

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.

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
  
• Ventilation roof spaces – including air spaces for roofs and under roof insulation and roof sarking not to ‘saturate’ roof and either whirly birds, ridge or eave vents. 
  
• More substantive and targeted education material particular
  
• 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.

Waterproofing and weatherproofing

Issues associated with waterproofing and weatherproofing continue to be a significant focus for governments and codes and standards writing bodies. HIA’s Technical Services team are receiving the most calls on these topics.

NCC 2022’s range of proposals related to waterproofing and weatherproofing include:

• DTS Provisions for waterproofing included in the NCC itself as opposed to purely relying on accessing and purchasing the waterproofing standard.
  
• Updated and more specific application of the external waterproofing provisions.
  
• Revised edition of AS 3740 waterproofing standard
  
• For the first time in 23 years Volume One will include some DTS Provisions for external weatherproofing of Class 2-9 buildings
  
• Updated and clarified external walls (fire safety provisions) for Class 2-9 buildings in line with the weatherproofing provisions
  
• Restrictions on use of water resistant plasterboard in shower areas and limiting the types of materials that can be as the structural substrates for shower areas for Class 2, 3 and Class 4 buildings
  
• Inclusion of mandatory fall/grade requirements to secondary floor wastes where one is installed.

Australian Standards

Alongside the NCC changes, a number of key Australian Standards are also being amended for NCC 2022 adoption. These include:

• AS 3740 (waterproofing – internal) 
  
• AS 4055 and AS 1170.2 (wind loading standards)
  
• AS 3500 (plumbing and drainage)
  
• AS 3959 (bushfires)
  
• AS 1428.1 (accessibility)
  
• AS 1288 Glass in buildings Selection and installation
  
• AS 4200.1 and 4200.2 (insulation and building wraps)
  
• AS 1684 Residential Timber framing construction
  
• NASH Standard for steel framing and bushfires
  
• FPAA Sprinkler standard.

The revision of these standards add to the enormity of changes being proposed for NCC 2022.

How to find out more about the changes

Key dates for the finalisation of NCC 2022:

• NCC 2022 public comment draft released for comment: 10 May 2021
  
• Comments close on public comment draft: 2 July 2021
  
• NCC 2022 proposed energy efficiency and condensation provisions released for public comment: 19 July 2021
  
• Comments close on energy efficiency and condensation proposals: 10 September 2021
  
• NCC 2022 preview published: May 2022
  
• Adoption of NCC 2022: 1 September 2022 (subject to likely transition periods for major policy items).

HIA is hosting a national series of face-to-face seminars in all capital cities and regional locations across June and July.
We will be alerting industry to the proposed changes, preparing them for the proposed changes if they are supported, and encouraging them to put in their own submissions and commenting on the draft proposals.

To register for these sessions, go to www.hia.com.au