NatHERS is updating the climate files to provide a more up-to-date climate data set that is more consistent and provides better accuracy in the assessment of energy use in residential homes. NatHERS Climate Files have not been updated since 2005.
The star bands are being re-calibrated because of the introduction of the updated climate files to NatHERS. This is to limit the impact of change, maintain the integrity of the scheme and avoid burdensome adjustment for industry. The star band re-calibration was based on limiting change to star ratings to an ‘average of zero’ for building types in a climate’s star band.
The updated climate files and re-calibrated star bands could mean that there will be a small change to individual house energy ratings depending on house design, building construction and climate zone.
Thermal bridging can significantly reduce the effectiveness of insulation if not accounted for. If the proposed thermal bridging provisions are adopted in the NCC, NatHERS will introduce thermal bridging to regulatory ratings to align with the other compliance pathways in the National Construction Code.
The proposed thermal bridging provision involves the impact of thermal bridging in steel framed houses to be factored into an energy rating, but only to the extent that it exceeds the thermal bridging impact of a timber framed house. The thermal bridging calculations to be installed in NatHERS only account for the additional impact that steel framing elements have over and above that of timber. The impact of introducing this approach to thermal bridging is expected to be up to 0.5 of a star rating.
NatHERS is being expanded to include Whole of Home assessments and ratings to support the proposed National Construction Code (NCC) requirements for residential buildings in 2022. This includes Class 1 dwellings and Class 2 sole-occupancy units (apartments), but not the common areas of apartment blocks.
The expansion of NatHERS to include Whole of Home assessments and ratings will deliver industry a streamlined and cost effective approach to demonstrate compliance with the proposed NCC 2022 requirements.
The Whole of Home tools allow a wider range of appliances, and energy generation and storage to be assessed, than under the NCC Deemed-to-Satisfy elemental provisions.
The changes will help households improve a home’s energy efficiency and reduce energy use, which provides a range of benefits including lower energy bills, improved comfort and health for occupants, improved resilience of buildings to extreme weather and blackouts (peak demand), and reduced carbon emissions.
NatHERS accredited Whole of Home tools are anticipated to be available for use from September 2022, in line with the proposed National Construction Code (NCC) 2022 coming into effect. The NatHERS AccuRate Whole of Home Benchmark Tool will be available from this date.
A consultation version of AccuRate Whole of Home (WoH) Benchmark Tool is currently available. The purpose of AccuRate WoH is to provide a benchmark that other Whole of Home tools can be measured against as part of the Whole of Home software accreditation under NatHERS. See the NatHERS Whole of Home software developer expression of interest page for more information on the software accreditation process and how to apply.
The accreditation of other tools cannot commence until final decisions on NCC 2022 energy efficiency provisions are confirmed. This means that other tools may not be available by 1 September 2022. The NatHERS Administrator is working closely with potential tool developers and is providing early access to information to help support their development.
NatHERS has endorsed the FirstRate5 Whole of Home Pilot Tool to provide an early indication of other NatHERS accredited tools that may be available in the future. Endorsement means that the tool includes all the key modules for a Whole of Home assessment and is on the right track for NatHERS accreditation. More information about the FirstRate5 Whole of Home Tool is available here.
Endorsed tools demonstrate what is possible for accredited NatHERS Whole of Home tools, by providing an indication of the look, feel and usability. Endorsed tools do not produce a NatHERS Certificate or Whole of Home rating.
It is not expected there will be an increased need to use AccuRate to do Whole of Home assessments and ratings. More tools are anticipated to be available for use from September 2022, when the National Construction Code launches. The FirstRate 5 Whole of Home Pilot Tool was recently endorsed by the NatHERS Administrator and is progressing to accreditation.
You need to know how to use AccuRate Whole of Home including how to generate an AccuRate Thermal assessment to use the Benchmark Tool. A number of training sessions have already been held by the NatHERS Administrator and a video demonstration of how to use the Benchmark Tool is here.
NatHERS tool endorsement provides an early indication that the tool is on the right track for NatHERS accreditation. Importantly endorsement provides the opportunity for the NatHERS Administrator to work with the Software Tool Developer to assist with any issues that may arise during the Whole of Home tool development process. Endorsed tools cannot be used to produce a NatHERS Certificate or a Whole of Home rating.
Tool accreditation means tools are formally recognised by the NatHERS Administrator as being ready to use for Whole of Home assessments and ratings. See the NatHERS Whole of Home software developer expression of interest page for more information on the software accreditation process and how to apply.
Sustainability Victoria has developed the FirstRate5 Whole of Home Pilot Tool and recently it has been endorsed by the NatHERS Administrator. The pilot tool is intended to help designers become familiar with undertaking NatHERS Whole of Home assessments, which are expected to form part of Performance Requirement 2 (PR2) in the proposed changes to the National Construction Code in 2022 (NCC 2022).
Please note that the FirstRate5 Whole of Home Pilot Tool cannot be used to assess compliance with NCC 2022. An updated version of the tool will be released in 2022, once all requirements for NCC 2022 are known.
The FirstRate5 pilot tool works by importing the heating and cooling load data from a FirstRate5 project file and then adding on the additional appliance and distributed energy modules. The user interface is simple to use, and it is expected it will only take 10-15 minutes to enter the necessary details to complete a Whole of Home assessment.
The FirstRate5 Whole of Home Pilot Tool has limitations at this stage:
The ‘Solar Panels and Battery Storage’ module is currently limited to 13 Victorian NatHERS climate zones (20, 21, 22, 24, 25, 27, 60, 61, 62, 63, 64, 66, 69), which have minimal crossover with climates zones along the NSW & SA borders.
Heating/cooling equipment efficiency and type can only be specified for two main zones: 1) the conditioned living (primary) zone, and; 2) the conditioned other (secondary) zone.
The efficiency level of the solar-electric, gas boosted solar and heat pump water heaters can be specified as either ‘standard’ or ‘high efficiency’.
An assessment can only be undertaken with a FirstRate5 project file.
Sustainability Victoria is offering free online one hour training sessions to interested parties. It is mandatory to attend a training session before Sustainability Victoria will grant you access to the pilot tool.
Visit Eventbrite to select a training session. If you cannot attend any of the listed sessions, please register your interest here and Sustainability Victoria will inform you about upcoming training sessions. Once you have been granted access to the pilot tool you can access it here.
To use the FirstRate5 Whole of Home Pilot Tool, you will also need to have an active FirstRate5 account. If you are not already a registered FirstRate5 user, you will need to visit the FirstRate5 website and create an account for free.
The NatHERS star rating and the Whole of Home rating will both be used to meet compliance with the NCC.
The NatHERS star rating will be used to meet compliance with the proposed Performance Requirement 1 (thermal performance) for Class 1 dwellings and J1P2 for Class 2 sole occupancy units (apartments).
The Whole of Home rating will be used to determine compliance with the proposed Performance Requirement 2 (annual energy use budget) Class 1 dwellings and J1P3 for Class 2 sole occupancy units (apartments).
The Deemed-to-Satisfy (DTS) point on the Whole of Home rating scale to meet the stringency proposed for NCC 2022 has not yet been set.
The rating scale aims to provide a point that can be used as the DTS provision for NatHERS, to demonstrate compliance with the NCC’s proposed Performance Requirement 2 (annual energy use budget) for Class 1 dwellings and J1P3 for Class 2 sole occupancy units (apartments).
The Australian Building Codes Board (ABCB) is consulting on a proposed new minimum NatHERS star rating of 7 stars for NCC 2022, with allowances for outdoor living area and/or ceiling fans in NCC climate zone 1 and 2.
Thermal bridging can significantly reduce the effectiveness of insulation if not accounted for. If the proposed thermal bridging provisions are adopted in the NCC, thermal bridging will be introduced to NatHERS to align with the other compliance pathways in the NCC. Thermal bridging will be based on calculation methods in NZS 4214.
When conducting a NatHERS energy assessment, the star rating is based on the total amount of energy predicted to be needed to keep that house comfortable. That total is broken down into the amount required for heating and cooling and is displayed on the NatHERS Certificate as well as the star rating.
To meet NCC requirements, a house design must meet the minimum energy requirements for a given location (total energy use) and must not exceed either the heating or cooling load limits for that star band and location.
The ABCB Standard that sets out the NatHERS split heating and cooling load limits will be updated in NCC 2022, to reflect the changes to NatHERS climate files and the associated changes to star bands. These updates mean the amount of energy corresponding to each star band is changing, so the accepted split of that energy into heating and cooling limits must also be adjusted.
The split loads will be updated using the same principle, whereby they will exclude the worst 5% of heating loads and the worst 5% of cooling loads, extrapolated from historical data recorded in the Australian Housing Data portal.
For almost 30 years, the Nationwide House Energy Rating Scheme (NatHERS) (www.NatHERS.gov.au) has provided energy performance ratings for new Australian homes, making them more energy efficient and comfortable to live in.
NatHERS will soon have the ability to include In Home energy performance ratings for established homes, which do not require plans and building specifications.
The National Scorecard is already offering this type of rating and will be phased into NatHERS as the first step towards nationally consistent In Home energy assessments under NatHERS.
The National Scorecard is an energy rating for established homes. It provides consistent, objective and robust ratings. People are able to compare energy costs between homes or gain an understanding of how they can improve the comfort of their own home and reduce energy bills.
Scorecard assessors are accredited by government. They have existing qualifications and/or skills and experience and undertake training before passing an exam to become accredited. Assessors are not employed by government and set their own fees.
Anyone wanting to improve the energy performance of their homes can engage a National Scorecard assessor. This may be before a major renovation or when selling or buying a property.
Assessors visit a home and record data in the Scorecard tool. They then produce a certificate before going through the results with the householder, making expert recommendations based on individual needs and circumstances.
The Scorecard is currently endorsed by NatHERS as an in home tool.
Voluntary in home energy assessments help make homes more comfortable to live in and help to reduce energy use and costs. An assessor visits a home to collect data about the home before providing advice on cost-effective upgrades and their use, which will improve the home’s energy performance.
Assessments take into account the comfort of the home in hot and cold weather extremes, and the energy used by major fixed appliances, such as air conditioners, heaters and hot water systems.
No. NatHERS assessors have the option of undertaking additional training to become a NatHERS endorsed Scorecard assessor. Alternatively, other people with the appropriate level of skills and experience in performing in home assessments, but no formal qualification, can also apply for entry into the Scorecard training.
NatHERS assessors use floor plans and building specifications to assess and provide an energy rating for a new home or major renovation at the planning stage. A home visit is not required.
A National Scorecard in home assessment does not require floor plans. A trained and accredited assessor visits a home. Information is collected and used to provide the home’s energy rating. An assessment typically ranges from $250 to $500 and takes around 2-3 hours to complete.
The National Scorecard tool has also been tested against the NatHERS Whole of Home tool, currently in development, with initial testing showing correlation across two house designs in seven climates.
Once the NatHERS In Home assessment processes (such as tool accreditation, Assessor Accrediting Organisations accreditation, In Home Certificate, etc.) are finalised, further refinement will be undertaken to align the National Scorecard tool with NatHERS.
NatHERS In Home assessments and the National Scorecard tool can be used across Australian in all climate zones.
The National Scorecard tool has been piloted and trialled nationally to ensure it can rate a diverse range of buildings, appliances and locations.
By early 2022, over 5,000 Scorecard assessments have been completed across Australia, with more than 80 assessors accredited across states and territories.
Assessments conducted in tropical areas consider important features such as cross-flow ventilation and ceiling fans. Assessments in temperate climates consider features important to manage both hot and cold weather extremes.
For tropical climates, the National Scorecard tool has been tested in the field by skilled assessors with local knowledge in locations including Cairns, Broome, Darwin and Townsville. It was found to be suitable for use in all of these locations.
The National Scorecard Initiative enables energy performance assessments to be conducted on established homes of any age or location, without the need for plans and specifications.
Accredited assessors use government supported National Scorecard tool. Assessors provide a certificate with a star rating out of 10 indicating the cost to run the fixed appliances in the home, ratings for comfort and the main factors influencing energy consumption in the home.
Accredited National Scorecard assessors assist home owners to better understand their home’s energy performance and provide expert advice on steps they can take to improve the comfort of their home and reduce their bills. The assessment certificate provides options on simple, energy-efficient upgrades which are discussed during the assessment appointment.
'NatHERS endorsed' means the tool, training and accreditation aligns with what NatHERS In Home assessments will require in the future, although some amendments are expected as requirements are agreed and finalised.
The National Scorecard Initiative (assessment tool, training and accreditation and quality assurance) was endorsed by meeting the criteria and standards set by the NatHERS Steering Committee. The NatHERS Steering Committee is a government body that oversees NatHERS.
The National Scorecard Initiative submitted documentary evidence for each criterion. The NatHERS Administrator assessed the evidence and the NatHERS Steering Committee endorsed the National Scorecard Initiative as having met the requirements.
Currently endorsed by NatHERS, the Scorecard is expected to commence the accreditation process from mid 2022. Until this transition is complete, all elements of the Scorecard, including the assessment tool, training and assessor accreditation, will continue to be delivered by the Victorian Government on behalf of all Australian governments.
The Commonwealth, state and territory governments are extending NatHERS to include Whole of Home and In Home energy ratings. Each assessment suits a different need.
NatHERS In Home assessments are designed for householders with an established home who wish to learn more about their home’s energy performance, cost, greenhouse gas emissions or comfort. These assessments rate the home by collecting information from a visit to the home. These assessments are designed to guide decisions for energy upgrades that can improve comfort, energy efficiency and minimise running costs and greenhouse gas emissions.
NatHERS Whole of Home assessments are an extension of the current NatHERS (thermal) assessment of new homes and renovations. These assessments will incorporate heating and cooling, hot water systems, lighting, pool/spa pumps, on-site energy generation, cooking and major plug-in appliances (e.g. air-conditioners). No home visit is required as these assessments will use plans and specifications to assess the home. They can be used for assessing the designs of new builds and major renovations and are a pathway to comply with the National Construction Code.
NatHERS assessments provide a star rating out of 10 which represents the energy performance of a home's building shell based on plans and specifications. More star ratings mean less heating or cooling is needed to keep a home at a comfortable temperature.
The National Scorecard star rating represents the average energy cost to run a home. It has a scale of one to ten and includes the home’s building shell, major fixed appliances, as well as any on-site energy generated from solar panels. Separate comfort ratings show the home’s performance in hot and cold weather. Efficiency ratings are also provided for the major fixed appliances along with the proportion of energy used by each appliance type.
Once NatHERS Whole of Home and In Home are fully established, the National Scorecard will be accredited as a NatHERS In Home rating tool, allowing NatHERS to offer a national home energy rating system that covers both new and established dwellings.