Australia’s construction industry has a robust building regulatory framework to ensure safe, accessible, and sustainable buildings. The National Construction Code (NCC) is the primary regulatory instrument, and it sets the standards for building design and construction. The NCC incorporates energy efficiency goals which aim to address climate change and reduce greenhouse gas emissions.
Deemed-to-Satisfy (DTS) provisions within the NCC provide solutions for meeting regulatory performance requirements. Sometimes the DTS provisions can limit design flexibility and may not be suitable for complex projects. Performance Solutions offer a tailored approach that allows for more flexibility in the design, whilst still meeting the energy efficiency standards. A performance solution is unique because it can allow any material or construction method to comply if the performance is equivalent to the DTS standards.
What is a Performance Solution?
A Performance Solution is used to show that the performance requirements of the NCC have been met. This is done by using one or more of the four assessment methods outlined in the Building Code of Australia (BCA).
1. Evidence of suitability
This method requires evidence to support a claim that a material, construction type or design meets the performance requirements or DTS provisions.
2. Verification Method
This is a special type of test or calculation methodology that determines if a building meets the performance requirements. This method compares the proposed building (as it will be built) to a reference building.
Typically, the referencing building is modelled in accordance with strict modelling criteria as set out in the NCC. Alternative methods outside of the NCC may be used, however the appropriate authority will take into consideration the relevant methods and provisions of the NCC.
3. Expert judgement
This employs the expertise of a qualified professional to determine whether the Performance Requirements have been met. This method is typically used in combination with other assessment methods to further support the outcome. It may also be used where physical criteria cannot be tested or modelled by calculation.
4. Comparison with the DTS Provisions
Like a verification method, this methodology requires the proposed building (as it will be built) to be compared to a reference building. Typically, the reference building is modelled according to the DTS provisions. If it can be demonstrated that the proposed building has performance equivalent or better than the reference building, then it is deemed to meet the performance requirements.
Performance Solutions And Energy Reports
There are various performance solution methods available in the NCC. Some of the common methods include:
Green Star and NABERS
These rating systems assess the environmental performance of commercial buildings across various criteria, including energy efficiency, water use, waste management, indoor environmental quality, and innovation. By achieving a high rating, buildings can demonstrate their commitment to sustainability and potentially attract tenants and investors.
Green Star
Green Star is a voluntary sustainability rating system that was launched in 2003 by the Green Building Council of Australia (GBCA). It was designed to assess the sustainability of projects throughout their life cycle. Green Star benchmarks projects across 9 categories:
- Management
- Indoor Environment Quality
- Energy
- Transport
- Water
- Materials
- Land Use & Ecology
- Emissions and Innovation
Points are awarded across each category on a scale from one to six stars, with 6 stars being considered “world leadership” performance.
NABERS
NABERS (the National Australian Built Energy Environment Rating System) is an Australian national initiative that is managed by the New South Wales Government. Only an independent ‘accredited Assessor’ can conduct a rating.
The rating system helps to measure the environmental performance of a building and provides a rating that is valid for twelve months. The rating ranges from one to six stars, and measures the following categories:
- Energy
- Water
- Waste
- Indoor environment
Government tenants in NSW are required to have a 4.5-star energy rating, and other states have adopted similar policies. In addition, owners of office buildings across Australia are required to disclose the NABERS Energy rating to prospective tenants or buyers.
VURB (Verification Using a Reference Building)
This method is specifically designed for residential dwellings. It provides a framework for assessing and verifying the energy efficiency and sustainability performance of new homes.
This alternative verification method will compare a reference building (DTS compliant), against the proposed building (as it will be built). Each building gets modelled in thermal software to calculate the annual energy consumption. If the proposed building uses less energy than the reference building, it is deemed compliant with the NCC.
EnergyPlus software such as DesignBuilder is most frequently used to demonstrate compliance. NatHERS software is unsuitable for VURB assessments because the software does not meet the modelling temperature requirements of the NCC.
NCC2022 imposes strict requirements for VURB and in most cases NatHERS returns more cost-effective results. In special cases, VURB may be suitable and can reduce construction costs.
JV3 Verification Method
A JV3 assessment is considered a performance solution that uses the Verification Method. A JV3 assessment involves simulating a building using EnergyPlus modelling software such as DesignBuilder. The NCC determines the parameters that must be modelled to the reference building.
The building must meet the following criteria to be compliant:
- The proposed (as-built) building must have total Greenhouse Gas Emissions lower than the reference building
- The proposed building must meet thermal comfort targets
By using JV3, building owners can meet compliance at a lower cost with greater design flexibility.
Thermal Modelling and Performance Solutions
Thermal modelling uses specialised software to create a virtual 3D model of a building. This model simulates how the building will perform under various climatic conditions.
By analysing factors like insulation, ventilation, and material choices, engineers can identify opportunities for optimisation and predict energy usage. This information is crucial for developing Performance Solutions that can improve building energy efficiency.
Thermal modelling is a valuable tool for assessing a building’s:
- Thermal comfort: Ensuring occupants experience comfortable indoor temperatures year-round.
- Energy performance: Evaluating heating and cooling loads to minimise energy consumption.
- Impact of design choices: Assessing the effects of different building materials, orientations, and shading strategies.
Performance Solutions rely on thermal modelling to demonstrate compliance with energy efficiency standards, particularly in cases where the Deemed-to-Satisfy provisions may be challenging. The JV3 Verification Method for commercial buildings and the VURB method for residential dwellings both use thermal modelling to assess energy performance and identify opportunities for optimisation.
When to Use Performance Solutions Over DtS
While Deemed-to-Satisfy (DtS) provisions can be suitable for many building projects, Performance Solutions may offer advantages in some circumstances. When a project involves unique architectural features or unconventional building systems, the DtS provisions may not be adequate. Performance Solutions will provide the flexibility to achieve desired outcomes.
If a project aims to exceed minimum energy efficiency standards or achieve net-zero energy usage, then Performance Solutions can help the design process.
Performance Solutions can also be used to tailor building design to local needs, ensuring comfort and energy efficiency in regions with extreme climate conditions.
Benefits for Stakeholders
Performance Solutions offer many benefits for the stakeholders involved in the building industry.
Architects and engineers gain greater design freedom and the ability to create innovative and sustainable buildings.
Developers and builders can achieve cost-effectiveness through optimised design and material selections, as well as lower operational costs.
Sustainability professionals have opportunities to demonstrate leadership in sustainable building practices and contribute to a greener future.
Contact Green Choice Consulting
By embracing Performance Solutions, Australia can continue to advance its building industry and create more sustainable and resilient built environments, while reducing resource consumption and saving on building costs.
With methods like Green Star, NABERS, VURB, and the JV3 Verification Method, we can achieve higher levels of energy efficiency, reduced carbon emissions, and improve the performance of our buildings.
Call 1300 864 944 or email Energy@greenchoiceconsulting.com.au to discuss your project. We have a team of accredited assessors and Section J Consultants who can provide energy efficiency assessments Australia wide.
