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7 Star NatHERS Certificate

Everything You Need to Know...

About the National House Energy Rating Scheme. Find out what the requirements are to certify your project today.

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A National NatHERS Requirements Guide

Everything you need to know about the NatHERS requirements per state. 

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7 Star NatHERS reports are a pathway to compliance for Energy Efficiency under Section 3.12 in the National Construction Code. Here you will learn all you need to know about energy efficiency compliance for residential construction projects in Australia. 

 

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What is 7 Star NatHERS exactly?

 

Are you looking for a NatHERS certificate for your next project?

At Certified Energy we take pride in helping our clients and their project achieve their full potential. Through the NatHERS assessment pathway, we can recommend thoughtful design solutions to reduce the environmental impact of your design whilst maintaining the vision of your project. 

 

What is NatHERS?

NatHERS is short for the Nationwide House Energy Rating Scheme. It uses a 10 star rating system to assess the thermal performance of dwellings across Australia. The National Construction Code (NCC) references these star ratings specifying a minimum number of star levels for all new houses built in Australia.

 

Often referred to as a NatHERS assessment, a house energy rating is required for all alterations and additions, and houses and individual units in apartments under Class 1 and 2 buildings detailed in the NCC, respectively.  This national assessment involves the thermal modelling of each individual room in a house to determine the modelled heating and cooling loads. 

 

NatHERS is the Nationwide House Energy Rating Scheme and uses a 10 star rating system to assess the thermal performance of dwellings across Australia. Within the NCC, minimum star ratings for developments are specified for all new houses built in Australia. However, in NSW, BASIX requirements supersede those outlines in the NCC. 
 
There are two main certification solutions that we use here at Certified Energy to achieve building compliance. These include the Deemed to Satisfy solutions as well as the Alternative Solutions.
 

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Deemed to Satisfy Solutions:

  1. House Energy Rating Scheme (HERS)
  2. Elemental Provisions (EP)

 

Alternative Solutions:

  1. Verification Using A Reference Building (VURB)
  2. State Specific Energy Protocols

 

Our team at Certified Energy will guide you through the various approval pathways to help your project achieve the necessary compliance.

 

What Is an Energy Rating?

An Energy or Thermal Efficiency star rating is an accurate indicator as to how much heating or cooling is necessary to keep your development comfortable. The energy rating generated by an accredited NatHERS assessor using licensed software indicates a dwelling’s efficiency in preserving energy (does not consider energy consumed by appliances). By improving your energy rating, you will require less active energy consumption to keep your dwelling thermally comfortable. 

 

What do the stars represent in the NatHERS rating?

The possible 0 to 10 stars is a scale that indicates the energy efficiency of a dwelling. If a dwelling is rated 0 stars, that means it offers no insulation from the external temperature. For example, if it is 20 degrees outside it will be 30 degrees inside. A 10-star dwelling is able to maintain a comfortable internal temperature all-year-round despite external temperatures. Hence, the more stars a dwelling has, the less energy it consumes, therefore reducing energy expenses.

 

What benefits does an energy rating give me?

When simulating the thermal performance of your dwellings, we will ensure that your energy expenses are reduced and that a healthy living environment is delivered through calculated and accurate methodologies. Doing so can ultimately be cost-effective in the long-term and increase property value.

 

Who Can Perform a NatHERS Assessment?

Only assessors trained, certified and accredited by 1 of the 2 nationally operating Assessor Accrediting Organisations (AAOs) can use NatHERS second generation thermal assessment software to provide official thermal efficiency star ratings and issue relevant certificates. The two AAOs are the Australian Building Sustainability Organisation (ABSA) and the Building Designers Association Victoria (BDAV). At Certified Energy, our assessors are accredited by the Australian Building Sustainability Association (ABSA).

 

Why choose Certified Energy as your NatHERS assessors

Our years of experience enables us to assess your project with unrivalled cost and time efficiency; whilst also maintaining the integrity of your designs. Normally, assessors provide thermal performance figures that meet the standard requirements in order to obtain compliance. However, for a small additional fee, we can optimise the use of energy saving measures so that they are placed effectively whilst still complying with the regulatory requirements. Our assessors also follow the Assessor Code of Practice and are given ongoing support so they can provide you with a high quality of service. NatHERS Universal Certificates can only be issued by NatHERS Accredited Assessors, which includes the NatHERS logo, rating and stamp.

 

What it means to be part of the Australian Building Sustainability Association (ABSA)

The ABSA is a not-for-profit industry organisation that aims to improve Australian homes and buildings by ensuring they are sustainable. This includes ensuring that Australian buildings are designed to provide comfort and efficient use of energy resources. The Association supports building professionals and assessors with membership and training.

As part of the NatHERS Protocol, the Association is also an approved Assessor Accrediting Organisation (AAO). This means NatHERS accredited assessors are able to perform simulations in order to comply with Energy Efficiency requirements of the National Construction Code and Thermal Comfort in BASIX (NSW).

 

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How are NatHERS star ratings assessed?

NatHERS is assessed through a process of thermal modelling where the proposed dwelling is modelled using NatHERS approved software. The construction type, materials, glazing, lighting and insulation are used to assess the overall annual thermal performance of the project. Climate data within the software determines the development’s total heating and cooling load throughout the year, with specific heating and cooling targets outlined by NatHERS that need to be met.

NatHERS Accredited Software is used to calculate an energy efficiency star rating and is based on expected indoor temperatures. This is assessed by assessing the project’s design, climate and household use. The tool therefore does not take electrical appliances within the dwelling into consideration, other than the air flow from the dwelling’s ceiling fans.

 

Develop a simulation model

A NatHERS accredited assessor will enter data into the software which will generate a simulation model of the dwelling. The simulation model will include: sizes and functions of the rooms, sizes and specification of openings, building materials/windows/products, type of construction, dwelling orientation and location.

 

Determining the temperature of the development

The simulation model will determine the level of heating or cooling temperature that is needed for occupants to remain comfortable within the dwelling.

 

Determining the need for heating and cooling systems

The NatHERS Accredited software model will determine the need for heating and cooling systems when internal temperatures fall outside of a comfortable range. This is based on assuming that occupants will open and close windows, blinds or awnings in an attempt to restore a comfortable temperature level prior to using the heating or cooling system.

 

Calculating a rating out of 10

Once the steps above have been completed, the total annual estimated levels of energy efficient heating and cooling are determined by a ranking out of 10 stars.

 

 

 

WHAT IS A 7 STAR RATING?

The National Construction Code (NCC formally known as the BCA) will soon require all new residential dwellings in Australia (Except NSW)* to achieve a minimum of a 7 Star Rating using the Nationwide House Energy Rating Scheme (NatHERS), approved software.

 

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 This NatHERS software estimates the internal temperature in each room of a dwelling for each hour of the year based on assumptions about occupant behaviour, information about the structure and specification of the dwelling and standard weather data for the dwelling's location.

The internal temperature is compared against a comfortable temperature range and occupancy pattern to estimate the annual heating and cooling loads per square metre of floor area to keep the temperature within the comfort range. The loads are adjusted and converted into a star rating between 0 and 10. A 10 star home is unlikely to need any artificial cooling or heating to maintain comfortable internal conditions, whereas a 0 star home would offer virtually no protection from the external temperature.

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Certificate

Comfort, Energy & Water

 

How are NatHERS star ratings assessed?

NatHERS is assessed through a process of thermal modelling where the proposed dwelling is modelled using NatHERS approved software. The construction type, materials, glazing, lighting and insulation are used to assess the overall annual thermal performance of the project. Climate data within the software determines the development’s total heating and cooling load throughout the year, with specific heating and cooling targets outlined by NatHERS that need to be met.
NatHERS Accredited Software is used to calculate an energy efficiency star rating and is based on expected indoor temperatures. This is assessed through the project’s design, climate and household use. The tool therefore does not take electrical appliances within the dwelling into consideration, other than the air flow from the dwelling’s ceiling fans.

 

Develop a simulation model

A NatHERS accredited assessor will enter data into the software which will generate a simulation model of the dwelling. The simulation model will include: sizes and functions of the rooms, sizes and specification of openings, building materials/windows/products, type of construction, dwelling orientation and location.

 

Determining the temperature of the development

The simulation model will determine the level of heating or cooling temperature that is needed for occupants to remain comfortable within the dwelling.

 

Determining the need for heating and cooling systems

The NatHERS Accredited software model will determine the need for heating and cooling systems when internal temperatures fall outside of a comfortable range. This is based on assuming that occupants will open and close windows, blinds or awnings in an attempt to restore a comfortable temperature level prior to using the heating or cooling system.

 

Calculating a rating out of 10

Once the steps above have been completed, the total annual estimated levels of energy efficient heating and cooling are determined by a ranking out of 10 stars.

 

What does a NatHERS assessment include?

A NatHERS assessment includes NatHERS Accredited Software that is used to determine an energy efficiency rating. This is completed by a NatHERS accredited assessor who can be verified by the NatHERS logo on the Universal Certificate. A NatHERS Universal Certificate will provide information regarding the key design features of the dwelling, the building materials, and the scope used to generate the dwelling’s star rating.

 

Energy Rating

An Energy or Thermal Efficiency star rating is an accurate indicator as to how much heating or cooling is necessary to keep your development comfortable. The energy rating generated by an accredited NatHERS assessor using licensed software indicates a dwelling’s efficiency in preserving energy. Please note, it does not indicate the dwelling’s actual consumption of energy as that depends upon appliances installed and the way in which they are used (only assessable after occupancy). By improving your energy rating you will require less energy to keep your dwelling comfortable and therefore provide lower energy expenses as well as a much healthier environment.

 

Stars

The possible 0 to 10 stars, is a scale that indicates the energy efficiency of a dwelling. If a dwelling is rated 0 stars then it offers no insulation from the outside temperature. For example, if it is 20 degrees outside it will be 30 degrees inside. Whereas a 10-star dwelling is able to maintain a comfortable inside temperature all year round no matter what the outside temperature. Hence, the more stars a dwelling has the less energy it consumes, therefore reducing energy expenses.

 

Do appliances such as, air-conditioners, etc. affect star ratings?

Generally, no as NatHERS energy ratings are based on how well designed the dwelling will be. Appliances added to the building and are likely to be changed in the future are not taken into consideration.

 

Table of NatHERS appliances

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Requirements

What do you need?

 

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When is a NatHERS certificate required?

NatHERS certification is required for all new developments with multiple dwellings, however NatHERS can also be used if desired on single dwellings. It was developed in order to reduce the countries overall energy consumption along with the BASIX process. BASIX is a NSW government initiative designed to improve the environmental sustainability of residential developments. It sets out the minimum standards for compliance in the following three areas: water, thermal comfort and energy, and can be assessed at through various means such as DIY which does not require NatHERS thermal modelling. NatHERS is a national scheme that involves the thermal assessment of a development in order to generate a NatHERS energy rating, which can be used for the thermal section of the BASIX. NatHERS energy ratings are much more thorough, accurate and flexible than the BASIX thermal tool. In order to achieve the best thermal performance at the lowest cost we recommend using both BASIX and a NatHERS energy rating.

 

What are the requirements of a NatHERS certificate?

For an accredited assessor to assess a project through the NatHERS process, they require the full plans, sections and elevations for the building as well as the building materials and glazing types that are intending to be used so that the building can be simulated accurately.
 
Generally, appliances such as, air-conditioners, etc. do not need to be known by the assessor as they do not affect the star rating as NatHERS energy ratings are based on how well designed the dwelling will be. Appliances that are added to the building and are likely to be changed in the future are not taken into consideration.
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The  National NatHERS Requirements Guide

Everything you need to know about the NatHERS requirements per state.

 

TIME

How long does it take for NatHERS Certification?

Small projects can be NatHERS modelled in 2-3 hours, and turned around within 24 hours. Larger multi-dwelling projects can take up to 5 days to model.  

 

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Cost

How much does it cost?

 

What Benefits Does an Energy Rating Give Me?

Our careful consideration when simulating the thermal performance of your dwelling(s) will ensure that your energy rating delivers many benefits including:
– Accurate results
– Reduced energy expenses
– Reduced cost of complying with BASIX
– Increased property values
– Sustainable buildings
– Healthier living environments

 

The cost for NatHERS certification depends on the size and complexity of the project, depending on the amount of time that is required to fully model and assess the building. 

 

 

 

7 Star Energy Rating- The New Minimum

What you need to know:

- State and territory ministers will meet in July to review the 11-year-old laws

- Climate Council and the Property Council of Australia are now pushing to make a 7-star energy rating the new minimum

- Living in a 7-star energy-efficient, all-electric, home would cut your energy bills by an average of $450 a year

- The move to a 7-star energy rating will reduce emissions by 25% each year, which is the equivalent of one car. 

16% of new housing are already being built to the 7-star energy rating, according to a 2022 report from CSIRO.

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GREEN HOME LOANS FOR 7 STAR ENERGY RATING HOMES

With buildings in Australia accounting for nearly 25% of carbon emissions it is not surprising that buyers are looking to build more sustainable homes.

A 2020 CSIRO study found that more than 9 million homes in the country do not meet the 7 star Nationwide House Energy Rating Scheme (NatHERS) rating that deems a property sustainable. With only 10% of new homes built received a 7-star rating or higher.

Thus, with the target of building more 7-star energy rating homes, banks and lenders are now offering special green home loans to borrowers that are buying or building eco-friendly homes.

WHAT IS A GREEN HOME LOAN?

A green home loan is a type of loan that encourages borrowers to buy, build or renovate their homes in an environmentally friendly way. These loans offer discounted rates for homes that pass an eco-friendly threshold. In order to qualify for one of these loans, your future house should pass at least one of these qualifications:*

- A 7 star or higher rating under NatHERS.
- Sustainable property upgrades, this includes:
    - Installation of real-time energy monitoring systems.
    - Hot water pump or solar hot water system.
    - Upgrade to LED lights for at least 75% of all light fixtures.
 
*Specific qualifications will vary from lender to lender
 

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ENERGY RATING CONSULTANT

Certified Energy, is a medium-sized company with over 12 people working with us and 15 years of experience in the ESD field. We take pride in the thoroughness of our assessments and often find that the quality of our work has a high standard, is precise, and lives up to the latest requirements of your NatHERS assessment needs. We can deliver projects quickly and resolve difficult or nonstandard situations with great expertise.

Here are 4 tips we think you should know before choosing your energy rating consultant.

  1. Check qualifications; always choose your consultant based on their relevant building industry degree qualifications, anything from engineering, architecture, or building background should suffice.

  2. When you are on a deadline, choose an ESD Assessor which has a minimum of 3-4 people working for them. 95% of the ESD Assessors have at least 3 consultants doing their energy assessments and will be able to respond fast.

  3. Every ESD consultant should be able to discuss certain aspects of a NatHERS assessment, ask if they collaborate together, and can advise you about the best case practices when doing a NatHERS report.

  4. What about their past project experience? Can your Assessor give you a good referral?

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DESIGNERS GUIDE TO INSULATION

Choosing the correct insulation applications for your project for optimal thermal comfort and reducing or removing performance glazing.

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Sample House Energy Rating Certificate

Every certified NatHERS project has a HERS certificate provided for the project. See how each of the elements of the building fabric are detailed and specified in these reports. 

 

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