Much has been said on the suitability, cost, benefits and impacts of the National Construction Code (NCC) 2022 energy efficiency and condensation changes. 

But what can’t be argued is that the changes are a significant shake up of the code, and the first major star rating stringency upgrade since 2011. It has certainly got the industry talking.

The new requirements will mean changes for both houses and apartments, requiring much more detailed attention to house and apartment designs, and building materials selections, to ensure compliance.

Energy efficiency changes for houses

NCC 2022 will introduce a number of energy efficiency changes to new houses (Class 1 buildings) and major renovations and extensions. The building fabric will need to achieve 7 stars (or equivalent) as opposed to the current 6-star rating. Homes will require higher window and glazing performance, with increases in the required ceiling and wall insulation R-values.

This will also mean changes to building designs and house layouts, greater attention to wall and roof colours in various climate zones as well as changes to structural floor systems (either insulated slabs or sub-floor insulation in most regions).

Other major changes include:

• a significant rewrite of the DTS Provisions of Part 3.12, to be at a 7-star equivalence
• new requirements for treating thermal bridging of steel framing, including cavities, upgrading insulation or rigid board insulation to the wall frame
• more stringent provisions for heating and airconditioning systems, and hot water systems
• new whole of house energy budget provisions to determine the total energy use of fixed building services, with recognition of potential offsets such as solar PV panels 
• an update to the verification using reference building method to achieve 7-star equivalence
• a new quantified Performance Requirement for the new energy budget provisions
• an upgrade of the star rating tools to incorporate a whole-of-house rating combining the thermal fabric (star rating) and the energy use budget requirements. 

Overall, the provisions bring increased complexity and mean the role of the building designer, product specifier and energy assessor become much more critical.

Energy efficiency changes for apartments

New apartments (Class 2 buildings) will need to achieve an average of 7 stars across the apartments in the building, with no individual apartment less than 6 stars (under NCC 2019 this is set at a 6-star average and no apartment less than 5 stars).

The other major changes include:

• new elemental DTS Provisions for Class 2 buildings set at 7-star equivalence (this will provide a second pathway for apartments to verify compliance)
• a new verification using reference building method for Class 2 buildings
• new requirements for thermal bridging of steel framing
• new provisions to create solar ready zones for future installation of onsite renewables;
• making provision for future installation of electric vehicle charging equipment for 100 per cent car parking spaces for Class 2 buildings.

A lot of the attention on NCC 2022 energy efficiency and livable housing requirements has been on Class 1 buildings, but for apartments, the new requirements will have an equal, if not greater, impact on designs, building layouts and compliance outcomes. Coupled with the impacts of the NCC 2016 and 2019 changes, apartments were once considered the more cost-effective housing choice. But they are now being impacted by rapidly escalating construction costs.

When will the changes take effect?

Alongside the new livable housing requirements, the energy efficiency and condensation management changes will take effect from 1 October 2023.

This date is subject to transitional arrangements against which a house has been approved. Some states and territories have longer transition times and/or variations to adoption of the requirements.

Here is an overview of what each state* is adopting and when: 

• ACT will adopt livable housing and 7-star provisions from 1 October 2023.
• Queensland will adopt livable housing and 7-star provisions from 1 October 2023, though noting Queensland have a Queensland Development Code that provides a one-star credit where the home or apartment has an outdoor living area that satisfies certain criteria.
• NSW will not be adopting the livable housing provisions but will increase the BASIX thermal target to match 7-stars and the energy target, similar to the whole-of-home energy usage provision. There is no change to the water target under BASIX, but there is a new requirement to measure and report on the embodied emissions of key materials in the home. 
• Tasmania will adopt the livable housing provisions from 1 October 2024 but not adopting 7-stars.
• Northern Territory will make limited changes to 5-star energy efficiency requirements and adopt livable housing provisions from 1 October 2023.
• South Australia will adopt livable housing and 7-star provisions, with an extended transition period until 1 October 2024 (further exemptions for certain housing types are also currently being discussed).
• Victoria will adopt livable housing and 7-star provisions, with an extended transition period until 1 May 2024.
• Western Australia will adopt 7-stars from 1 May 2025 but not adopt the livable housing requirements.

*Adoption dates remain a dynamic area and may be subject to change.

Innovation in insulation

Innovation in insulation from companies such as Kingspan is offering solutions for industry to meet the new 7-star requirements. Killian Smith, Kingspan Insulation Technical Services Manager, says the NCC 2022 changes are significant and will see a greater focus on increased thermal performance in residential buildings. 

‘The development of the code has seen an emphasis on the use of insulation to improve energy efficiency and reduce heating and cooling costs,’ he says. ‘The use of high-performance insulation on walls and floors is an essential component of building design, which plays a crucial role in achieving a higher NatHERS energy assessment rating for buildings.’

Killian adds that the company’s preliminary modelling has revealed some welcome insights for its range of insulation products.

‘Kingspan Insulation’s preliminary modelling has shown by using Kingspan Residential Insulation within the traditional 90mm residential frame and underneath the concrete slab, the majority of the gap from 6 to 7 stars can be bridged.’

Keep calm and cool

Kingspan Insulation’s Kooltherm products are a great fit for the new NCC 2022 building standards. Their high-performance capabilities and excellent thermal insulation properties perfectly suit to meet the needs of the ever-increasing energy efficiency performance requirements of the Australian Building Code.

Kingspan Insulation Australia’s Kooltherm manufacturing facility is at the forefront of the industry, producing high-performance insulation products that are designed to meet the increasing demands for energy efficiency in residential buildings and market demand. The facility, located in Somerton, Victoria, uses state-of-the-art technology to produce insulation products that provide exceptional thermal performance.

For more information, call the Kingspan Insulation technical services team on 1300 247 235.

How about the condensation changes? 

NCC 2022 includes a broad range of condensation management measures covering wall sarking, ventilation and exhaust systems. 

Wall sarking

Changes to wall sarking requirements to specify the use of more vapour permeable types equivalent to Class 3 or Class 4 membrane, depending on the climate zone. 

Ventilation

Ventilating roof spaces will require: 

• maintaining air spaces for roofs between insulation and roofing
• additional roof space ventilation via installation of whirlybirds, ridge or eave vents or similar.

Exhaust systems

Exhaust system changes will include: 

• minimum flow rates for exhaust fans
• mandatory exhaust and ducting to the outside for rangehoods and exhaust fans
• banning recirculating rangehoods
• bathrooms not naturally ventilated must have exhaust fans with a 10-minute run-off timer
• additional provision for ventilation to laundries/bathrooms containing a dryer.

As a word of warning, there are lots of hidden details in applying and meeting these new provisions. They also apply differently based on the climate zone the home may be in.

Many of these changes will need to be designed into the dwelling from the outset. For example, floor framing type to allow ducting, or on bathroom/laundry designs as opposed to this being incorporated as part of fit-off time. 

Therefore, it is important to familarise yourself with these changes as they will apply to projects – along with the energy efficiency changes. Note that they also may apply in those states and territories that have varied the 7- star energy efficiency requirements, for example, Tasmania and Northern Territory.

Helping industry prepare

HIA is running another suite of dedicated energy efficiency and condensation changes seminars throughout July and August. These sessions will bring together a range of experts to provide a detailed breakdown of the new requirements, covering: 

• case studies and worked examples of 6-star vs 7-star homes 
• application of the new whole of home provisions
• ways to cost effectively meet the new requirements
• how to mitigate against the new thermal bridging changes
• contemporary materials and solutions to meet the new requirements different NCC compliance options
• the forgotten third reform area – the condensation management changes.

Register early to avoid missing out. Given the scale and complexity of the changes, these popular sessions will help industry understand the new requirements prior to them taking effect.

2023 HIA Energy Efficiency & Condensation Changes Seminars

* Further sessions in other regions will be held to align with NCC adoption dates

Brand promotion: This article was compiled with contributions from Kingspan Insulation.

Published on 16 June 2023