In this article, we provide information regarding the National Construction Code, what it is and why it’s essential for establishing safe and sustainable building and design practices.
The team at Sellar Thermal are proud to facilitate and assist with the Residential and Commercial Energy Efficiency compliance pathways.
The purpose of this article is to provide essential information regarding the residential energy efficiency compliance pathways contained within the National Construction Code – Volume 2, Section H6.
We ensure your new residential project or multi-dwelling development is both certified and council ready to comply with the most up to date NCC energy efficiency regulations.
To access our comprehensive guide regarding the NCC 2022 House Energy Efficiency compliance pathways, including design recommendations, please click below.
What is the National Construction Code of Australia?
The National Construction Code (NCC) serves as Australia’s key technical guidelines for building design and construction.
This code, based on performance standards, establishes the minimum safety, health, comfort, accessibility, and sustainability requirements for specific buildings.
The NCC is published in three volumes:
- The Building Code of Australia (BCA) is Volumes One and Two of the NCC and,
- The Plumbing Code of Australia (PCA) is Volume Three of the NCC.
NCC Volume One primarily covers the design and construction of multi-residential, commercial, industrial and public assembly buildings and some associated structures.
NCC Volume Two primarily covers the design and construction of smaller scale buildings including houses, small sheds, carports and some associated structures.
NCC Volume Three covers the design, construction and maintenance of plumbing and drainage systems in new and existing buildings.
Components of NCC Volume Two
NCC Volume Two contains the following sections:
Section A – Governing Requirements: which provide the rules and instructions for using and complying with the NCC; and include the following:
- Interpreting the NCC.
- Complying with the NCC.
- Application of the NCC in States and Territories.
- Applying documents referenced in the NCC.
- Documenting the suitability of the design, construction and/or use of materials to comply with the NCC.
- Classifying buildings by their characteristics and intended use.
Section H – Housing, which include the following:
- Part H1 – Structure
- Part H2 – Damp and weatherproofing
- Part H3 – Fire safety
- Part H4 – Health and amenity
- Part H5 – Safe movement and access
- Part H6 – Energy Efficiency
- Part H7 – Ancillary provisions and additional construction requirements
- Part H8 – Livable housing design
Part H6 – Energy Efficiency
Stellar Thermal are all about ‘thermal performance and energy efficiency’, so let’s explore NCC Vol 2 – Part H6 compliance in further detal.
Part H6 – Energy Efficiency provisions were established to ensure that buildings are designed and constructed to operate with a suitable minimum energy level based on their intended purpose and location.
The NCC has two different mandatory requirements:
- Performance Requirements outline certain criteria which must be met.
- General Requirements which cover other aspects of applying the NCC.
This includes its interpretation, reference documents, the acceptance of design and construction (including related evidence of suitability/documentation) and the classification of buildings within the NCC.
There are two performance requirements in the NCC Volume Two that reflect the key concerns for energy efficiency for Class 1 & 10 Buildings.
- H6P1 – Thermal Performance
- H6P2 – Energy Usage
H6P1 – Thermal Performance
One aspect of building performance is the thermal efficiency of the building envelope. By enhancing the building fabric’s thermal performance, it is assumed that the requirement for artificial heating and cooling will be reduced.
As artificial heating and cooling are major contributors to energy consumption in a typical Australian home, improving the building’s thermal efficiency should result in reduced energy resulting in lower greenhouse gas emissions over the building’s lifespan.
H6P2 – Energy Usage
The key objective to this performance requirement is to reduce energy consumption, energy peak demand and reduce greenhouse gas emissions.
Energy Efficiency Compliance Pathways
There are several pathways to achieve compliance with the NCC Vol 2 – Section H6 as listed below:
Deemed to Satisfy Provisions
The Deemed-to-Satisfy Provisions are a prescriptive approach to achieving compliance. They are similar to a recipe book, in that they tell you how, what and in which location things must be done.
In the case of designing and building a house they include the materials, energy efficiency components, design factors, and construction methods that, if used, are deemed to meet the performance requirements, hence the term “Deemed-to-Satisfy”.
A Performance Solution is unique for each individual situation.
These solutions are often flexible in achieving the outcomes and encouraging innovative design and technology use.
A Performance Solution directly addresses the Performance Requirements by using one or more of the ‘Assessment Methods’ available in the NCC.
Essentially, if you are building or designing a standard home, it will likely utilise a DTS Solution.
However, if you’re building or designing something a little outside the box, a Performance Solutions approach might be an alternative solution.
Note: According to the NCC, a DTS Solution is the most preferred pathway to compliance.
There are two verification methods available to achieve compliance:
H6V2 – Verification using a reference building.
This method can be used to comply with the ‘thermal performance’ part of H6P1, by comparing the performance of a proposed new building with a similar ‘reference’ building that meets the DTS provisions.
H6V3 – Verification of building envelope sealing.
This method can be used to comply with the ‘building sealing’ part of H6P1, as it tests the air leakiness of the building, or in other words, how well the external building envelope is sealed.
This is achieved by using a method called the ‘blower door test’.
Deemed to Satisfy Pathways of Compliance
Part H6 and Part H6D2 of the NCC Volume Two outline two DTS pathways for complying with the energy efficiency performance requirements of residential buildings as follows:
Pathway 1 – House Energy Rating Software (NatHERS)
The first method is to use the House Energy Rating software (NatHERS) by applying Specification 42 to achieve the heating and cooling thermal loads specified for a particular climate zone.
Pathway 2 – Elemental Provisions
The second method is to apply the Elemental Provisions by using Section 13 of the ABCB Housing Provisions Standard for Energy Efficiency.