NatHERS

What is NatHERS:

The Nationwide House Energy Rating Scheme (NatHERS) is an energy rating system used to assess the thermal performance for new dwellings, renovations, alterations and extensions. NatHERS uses a 10 star rating system to assess the thermal performance based on the home’s design, construction materials, insulation, glazing and climate zone.

The National Construction Code (NCC) references these star ratings and specifies the minimum star rating new homes and alterations/additions must meet in Australia. Whilst previously residential homes were required to achieve a 6 star rating, Under NCC 2022 the minimum star rating has been increased to 7 stars. The goal is to create more energy efficient homes helping you to save money on your energy bills.

In NSW, BASIX supersedes the NCC. Whilst BASIX assesses sustainability aspects, including water usage, energy efficiency, and indoor thermal comfort, NatHERS focuses on the building’s thermal performance, providing a star rating based on energy requirements for heating and cooling and is used in conjunction with BASIX to cover all aspects of the homes sustainability.

NatHERS does not currently cover the energy efficiency of appliances (such as air-conditioning or heating systems, solar panels, batteries, etc). The National Construction Code 2022 sees the introduction of NatHERS Whole of Home which includes a new approach that accounts for appliances, solar and batteries and will be become a requirement for new homes in 2023 (subject to state requirements).

Find out more about NatHERS - Whole of Home Assessment

What is involved in a NatHERS assessment:

NatHERS approved software is used to measures the thermal performance of a dwelling & determine the thermal comfort score. There is currently 4 licensed software programs for assessors to carry out assessment through including:

FirstRate5
Hero
Accurate Home
BERS Pro

Assessors must be trained in and hold accreditation in the specific software in order to use it to produce NatHERS certificates.

The buildings construction type, materials, glazing and insulation data is input into the software which then uses a thermal modelling engine to run a simulation of the dwelling. This simulation is used to determine the level of heating or cooling required to achieve a comfortable environment.

Based on this information, the software deliver a star rating that reflects the level of energy efficiency of the dwelling. Specific heating and cooling targets are set by NatHERS, which the dwelling must meet to achieve the minimum 7-star rating. In NSW, the simulation is required to be run against the BASIX heating and cooling targets.

To accurately model a home we require the following details:

A site plan showing the boundaries, house position, any buildings or element that provide shading including fences & neighbouring properties.
Floor plan showing the layout of the house including floor coverings.
Elevations showing the walls, roof and windows. Including wall and roof colours
Electrical plans showing any down-lights, exhaust fans and ceiling fans
Sections drawings if available to show ceiling and wall properties.

When should you get a NatHERS assessment:

Whilst an NatHERS/energy efficiency assessment can be carried anytime from the initial concept stage to the final design development/approval stage, it can be beneficial to your project to consult with us early in the project. We can provide advice/feedback on the design, orientation & features of your proposal from a passive/energy efficiency perspective before you fall in love with your design.

Who can undertake a NatHERS assessment:

NatHERS assessments must be carried out by a trained assessor holding a Certificate IV in one of the following courses:

Certificate IV in Home Energy Efficiency and Sustainability (Thermal Performance Assessment) – CPP41119
Certificate IV in Home Energy Efficiency and Sustainability (Home Sustainability Assessment and Thermal Performance Assessment) – CPP41119

In order to issue NatHERS certificates, assessors must be accredited with an Assessor Accrediting Organisation (AAO) and hold Professional Indemnity Insurance. There are three AAO’s that assessors can be accredited through.

All assessors are required to under going audits and must get 12 CPD (Continuing Professional Development) points each year.

Work with us

Due to the potential complexity of energy efficiency & NatHERS assessments, we will need to review proposals and provide quotes on a case-to-case basis to determine the best approach for your project.