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BASIX Certificate

Increase to BASIX Standards

The NSW Government has committed to achieving net zero emissions by 2050. This will improve the quality of life for the people of NSW, protect the environment and maintain a strong economy.

The Net Zero Plan Stage 1: 2020–2030 sets out how the NSW Government will deliver on our commitment to achieving net zero by 2050.

The Trajectory for Low Energy Buildings is a national plan that aims to achieve zero energy and carbon-ready buildings. For new residential development in NSW, the Trajectory is being delivered through the State Environmental Planning Policy (Sustainable Buildings) 2022

 In other states energy efficiency provisions will be included in the National Construction Code (NCC) 2022

Building homes to use less and greener energy

We are improving BASIX standards to build more comfortable homes, cut energy costs and contribute to our target of net zero homes by 2050. This is part of the Trajectory for Low Energy Buildings, a national plan that aims to achieve zero energy and carbon-ready buildings. The plan proposes increases to the energy efficiency provisions in the National Construction Code (NCC) for residential buildings from 2022.

BASIX has stopped 12.3 million tonnes of greenhouse gas from going into our air in the past 17 years. Our updated standards will help drive down emissions even further. The reforms will save another 150,000 tonnes of greenhouse gas a year the equivalent of running 31 wind turbines running for a year enough electricity to power 27,000 homes each year or planting around half a million trees. 

Basix new image

What do our new standards mean:

  • Cheaper energy bills. You’ll use less electricity so your bills will be cheaper – saving as much as $980 a year on energy bills.
  • More comfortable homes. Your home will be naturally cooler in summer, warmer in winter, which means you won’t be turning the heater or air conditioner on as often
  • Fewer carbon emissions. This contributes towards our goal of net zero homes by 2050

More than half a million NSW homes now meet BASIX energy and water saving standards.

This is an image of a BASIX diagram

Higher thermal performance standards

BASIX thermal performance standards are designed to limit the amount of heating needed in winter and the amount of cooling in summer. The limits are known as heating and cooling caps.  

The Nationwide House Energy Rating Scheme (NatHERS) estimates the amount of energy needed to heat and cool a home. 

The total amount of heating and cooling needed for one home can then be compared to another using the NatHERS scale of 1-10 stars. 

Homes built to the current BASIX standard range between 5.5 and 6 star NatHERS on average. The new thermal performance standards will increase to 7 stars.

This is the same thermal performance as that proposed for the National Construction Code in 2022. 

BASIX thermal performance and energy standards have increased for all new residential buildings across NSW except for:

 - homes in NatHERS Climate zones 9,10 and 11  on the north coast of NSW

- small apartment buildings up to 5 storeys in NSW

You can download the calculator to find out the current and proposed thermal performance standards with your postcode and building type.

Download the BASIX standards calculator

Table 1 Thermal performance standards changes 

Building type 

Current standards

Proposed higher standards

Detached or attached houses 

Heating and cooling caps to deliver average 5.5 – 6 NatHERS star outcomes 


7 NatHERS stars 

Revised heating and cooling caps 



Heating and cooling caps to deliver average 5.5 – 6 NatHERS star outcomes 


Maximum heating and cooling caps for individual apartments 

Average 7 NatHERS stars – across the building 

average heating and cooling caps  


Minimum 6 NatHERS stars – individual apartments 

maximum heating and cooling caps – individual apartment 

Climate data and the proposed thermal performance standards

BASIX thermal performance standards are developed using NatHERS to estimate heating and cooling loads. The NatHERS model is based on past meteorological records and has been updated to cover weather data up to the year 2015. It does not include future climate projections. 

Higher  energy standards 

BASIX Energy standards are expressed as a percentage reduction in carbon emissions from the pre-BASIX benchmark of 3,292 kg CO2-e/(person.year). 

The new energy efficiency performance requirements proposed for the NCC are quantified in terms of energy value or net cost to society. The BASIX energy standards continue to measure using carbon emissions.  

The  increase to BASIX energy standards will align with the proposed provisions of NCC in 2022.

The BASIX Energy standards are unique to climate zones defined by NatHERS

The proposed higher standards will continue to vary by home type and climate zone.

You can download the calculator to find out the current and proposed energy standards with your postcode and building type.

Download the BASIX standards calculator

Table 2 Changes to the higher standards for detached houses and high-rise apartment buildings 


Current Energy standards 

Proposed new Energy standards 

Detached houses 

Standards do not vary with floor area 

Standards will vary with total floor area. This is to account for energy consumption and the number of people that live at a property. For example, A small house with a floor area of 100m2 will have different standards to a large house with floor area of 250m2


High-rise apartment buildings 

The same standards apply to apartment buildings 6 storeys and higher. 

Two separate standards are proposed for high rise apartment buildings: 

- 6 – 20 storeys,  

-  21 storeys and higher. 

This will account for the energy consumption of shared services specified in high-rise buildings. 

Updating greenhouse gas emission factor of grid electricity 

The greenhouse gas emission factor is the amount of emissions (expressed as kilograms of carbon dioxide equivalent (kg CO2-e)) generated and transmitted from each unit of grid electricity to households. BASIX currently uses an emission factor of 1.062 kg CO2-e for each kilowatt-hour (kWh) of electricity. 

The NSW electricity grid has become greener as we produce more electricity from renewable energy sources. We plan to recognise this in the proposed new energy standards by updating the greenhouse emissions factor of grid electricity.  

Based on emission projection data obtained from sources such as the National Greenhouse Accounts Factors and the Commonwealth Department of Industry, Science, Energy and Resources (DISER), Figure 1 shows that the emission factor from grid electricity in NSW will be reduced significantly in the next two to three decades. 

A 10-year average from 2022 to 2031 (or 0.67 kg CO2-e/kWh) will be adopted for calculating BASIX energy scores from 2022. 

Figure 1  Emission projection for grid electricity from 2020 

Emission projection for grid electricity from 2020

Other changes to the BASIX energy section 

In response to feedback from stakeholders we are introducing the following changes to the BASIX calculations: 

  • Incorporating the NatHERS whole-of-home calculation to align with the national requirements planned in the NCC, including how the number of occupants is estimated.
  • Assuming installation of energy efficient lighting (such as LEDs) in houses and apartment units 
  • Updating the default efficiency settings of household appliances. For example, fridges and dishwashers.
  • Removing star rating selections of fridges and washing machines in apartment units to:
    • ensure that building designers are focused on improving building façade and fixed energy systems to satisfy BASIX energy standards. 
    • reduce waste if occupants move into new apartment units with their own fridge and washing machine. 

Users can continue to select star ratings of dishwashers and clothes dryers, as occupants often rely on these appliances to be installed in a new unit. 

  • For apartment buildings: 
    • Lift inputs and calculations will be revised to include lift banks and express zones. Tempered air supply will be an available option for the ventilation of lift lobbies and corridors. This is in addition to the current supply, exhaust and air conditioning options. 
    • Calculations to estimate energy consumption from central heat pump hot water systems with gas boosters will be revised to improve consistency with other available options. 

New Materials Index

The new BASIX Materials index will calculate and report on the embodied emissions of a home.

The online BASIX tool will calculate the embodied emissions of a home by estimating the volume of different materials used in the home’s construction and applying the emissions factors for the materials.

The emissions factors represent the embodied emissions from the production of each building material. Default factors for embodied emissions of materials are based on the well-recognised EPiC database. Although the initial materials index does not account for the full life cycle impact of building materials, other factors such as the durability and transport of building materials will be considered in future revisions.

The embodied emissions calculations have been tested by many users of BASIX, including builders adopting higher BASIX standards, ahead of 1 October 2023. This experience revealed a complex relationship between the thermal performance standard and embodied emissions. As a result, there will be no limit on embodied emissions of building materials when the policy commences on 1 October 2023. We will consider setting a limit (or standard) in the future after we have collected comprehensive data on the embodied emissions of development built to the new standards.

Increase to BASIX Standards exhibition

Increase to BASIX standards (as exhibited)

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