NatHERS Certificate: A Guidebook For Residential Developers in 2024

NatHERS Certificate: A Guidebook For Residential Developers in 2024

In Australia, the National Construction Code (NCC) Highlights the Minimum Energy Efficiency requirement for both commercial and residential buildings. NatHERS deals with residential buildings. NatHERs certificate highlights your commitment to sustainability.

In a recent study, it was found that Australians are willing to pay 5% more to purchase a home that’s energy efficient. So when you comply with NatHERS, you’re not just establishing your project eco-friendly, but you can also fetch a good value.

If you want to know more about what is NatHERS certificate is and how you can give a star rating for your residential project, you have just landed at the right place.

What is a NatHERS assessment?

NatHERS assessment represents a process of examining the energy efficiency of a residential structure. This NatHERS program have two fundamental aims:

  • Minimising energy usage in residential buildings.
  • Lowering greenhouse gas emissions.

Therefore, NatHERS-certified homes are also energy-efficient.

During the assessment, a certified professional will analyse the following components:

  • The architectural design of your home.
  • Construction materials used for building the structures.
  • The prevailing climatic condition of the region.
  • Energy performance of household appliances
  • Thermal comfort and dependency on HVAC system
  • Onsite energy production and storage (solar energy).

Based on this NatHERS assessment, your residential project will get a star rating ranging from zero to 10.

Types of NatHERS Rating

When you look at a NatHERS certificate, you will see two types of ratings:

  • The first is the NatHERS energy and thermal rating, where a star rating is assigned between 0 and 10 stars.
  • To attain the zero carbon goal, the Australian government introduced the Whole of home rating. This rating is based on a scale of 0 to 100 stars.

All residential projects developed following NCC 2022 will have both these ratings mentioned in their NatHERS certificate. This is similar to NABERS or JV3 Assessment for commercial building.

NatHERS Star Rating

As mentioned previously, NatHERs assigns a 0 to 10-star rating to residential buildings that have undergone the assessment.

The greater the star rating, the more energy-efficient your residential structure will be. Therefore, a higher NatHERS star-rated home is cheaper to operate and more comfortable to stay in.

Similarly a building with lower star rating will spend more on energy bills due to increased dependency on artificial  heating and cooling systems.

Here’s a quick example of how the rating system in the NatHERS certificate works:

  • 0-star rating: A home with zero star rating is uncomfortable to reside in. It will become extensively hot in summer and cold in winter. To maintain pleasant indoor temperatures, the residents will have to rely on artificial heating and cooling equipment.Consequently, the energy expenses of this home will shoot up considerably.
  • 7-star rating: This is the minimum star rating that you will require to obtain a NatHERS certificate. A home attaining a 7-star rating will need moderate heating and cooling to keep it comfortable to live in.
  • 10-star rating: Residential buildings featuring a 10 star rating are extremely energy efficient and comfortable to stay in. It’ll offer exceptional thermal comfort throughout the year with minimal to no dependency on mechanical heating and cooling. To achieve the rating on NatHERS certificate you’ll need to consider the local climate while designing your residential project.

NatHERS Whole of Home Rating

The Whole of Home rating is a new addition to the NatHERS certificate. It rates a residential structure between 0 to 100.

In 2019, Energy Ministers signed the Trajectory for Low Energy Buildings plan. This plan aims to attain zero-energy commercial and residential buildings in Australia.

The Trajectory proposed the expansion of the existing NatHERS to offer nationally accredited Whole of Home tools. This addition will support new requirements in the National Construction Code (NCC 2022).

Currently, several Australian states and territories are adopting the updated NCC for 2022. So, in the new NatHERS certificate, you’ll have two minimum requirements:

  • A minimum seven-star energy rating
  • A Whole of Home rating of 50 (out of 100).

The National Construction Code’s energy value metric serves as the foundation for the Whole of Home rating.

The energy value encompasses the following

  • Estimated energy usage cost,
  • Approximate cost to the energy network to support that home
  • The cost of carbon emissions is a result of the home’s energy consumption.

To determine the energy use, you’ll need to consider the home’s thermal performance, appliance energy consumption, and energy offsets by any onsite renewable energy production and storage (e.g., solar panels and batteries).

Step-by-step NatHERS Assessment Process

During NatHERS assessment the assessors will use accredited software to collect and enter information. After completion of the assessment the assessor will issue a certificate which will highlight the star rating of your residential during.

Here’s a quick overview of the assessment process:

  • The NatHERS Assessor will develop a design documentation for your dwelling.
  • Next is the review phase. During this step the assessor will review the information about the home’s design, construction, and other relevant information.
  • The NatHERS Assessor will draft a rating. As a builder or developer, you’ll need to review the rating. You might find some design modification suggestions based on the assessment findings.
  • If your design is perfect and you’ve consulted energy experts, you’ll require minimal to no changes. Once the change is implemented, the NatHERS Assessor will issue a NatHERS Certificate.
  • Only after you receive the NatHERS certificate can you begin the building work. And after the construction is completed and ready for possession you will get an occupancy certificate.

NatHERS is only applicable for new residential buildings or residential structures undergoing significant renovation. So what about existing structures?

The Residential Efficiency Scorecard can help with that. This tool is used to evaluate and rank the existing residential structures’ energy efficiency. In case of commercial developments existing building can follow NABERS rating while new constructions have the option to use DtS assessment or alternative JV3 Assessment to demonstrate compliance with NCC standards.

Wrapping Up

Energy efficiency in the commercial and residential building sector is gaining immense importance.  Therefore, to stay relevant in the industry and attend to the evolving needs of the customer, your building projects should comply with the energy efficiency standards.

To ensure your building project stays on track while adhering to energy regulations, You can hire a professional building consultant. They can help you understand the energy efficiency of your building and suggest ways to improve it.