What is a BASIX Certificate?
BASIX (The Building Sustainability Index) was introduced as part of the NSW Government’s 2004 initiative to ‘encourage sustainable residential development’ and is in effect part of the Environmental Planning and Assessment Act. The BASIX certificate aims to accommodate NSW with more resilient dwellings together with reducing greenhouse gases and water consumption.
BASIX was established to meet targets of up to 40% reductions in water consumption as well as greenhouse gas reductions by up to 25%. As a result, this delivers financial savings for the home owner.
BASIX Assessment
A BASIX certificate assessment is required for the development application process in NSW and considers various criteria, such as:
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Location of the building
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Orientation size of the building
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Construction type of the building
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Window size and type of the building
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Landscaping of the building
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Appliances used within the building.
Additionally, it also considers thermal comfort levels which lessens the amount of energy used by dwellings in order to heat or cool the house to a comfortable level.
As well as contributing to a sustainable future of urban planning, the homeowner will also financially benefit through reduced water and energy bills. Your BASIX certificate will confirm that your proposed project will abide by the NSW Government’s sustainability targets since obtaining a BASIX certificate means your residential building will have passed the government’s environmental targets.
Example BASIX certificate overview
When would I require a BASIX Certificate?
The development application stage of every new residential dwelling built in NSW of $50,000 or more require a BASIX certificate. Residential dwellings include:
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Single dwellings
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Dual-occupancy dwellings
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Townhouses
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Villas
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Low-rise, mid-rise and high-rise multi unit developments
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Boarding houses
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Guest houses
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Hostels
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Lodging houses
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Backpacker accommodation
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Multi-unit developments
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Swimming pools and/or outdoor spa with water capacity greater than or equal to 40,000 litres or 40 kilolitres.
Additionally, alterations and add-ons to existing dwellings which cost greater than $50,000 also require a BASIX certificate.
The development application (DA) stage of all new residential dwellings in New South Wales (NSW) requires a BASIX certificate. This applies to all new NSW dwellings that cost $50,000 or more.
The three types of residential developments include:
1. Single dwellings
Which includes singles houses on one lot, bungalows, one part of a semi-detached home, cottages and secondary dwellings.
The three components of sustainable design used to assess single dwellings include: water usage, greenhouse gas emissions and thermal comfort.
2. Multi dwellings
These include: two houses on one lot, dual-occupancy dwellings, townhouses, row houses, terraces, residential flat buildings, villas, low-rise, mid-rise and high-rise multi unit developments, boarding houses, hostels, lodging houses, guest houses backpacker accommodation, shop top houses and a new principal dwelling and a new secondary dwelling such as a granny flat.
The sustainability assessment of multi dwellings also considers the factors of water, energy and thermal comfort. The assessment tool for multi dwellings, however, is better suited to larger residential developments such as for car parks and shared gardens. These all use a larger abundance of water and energy compared to single dwellings.
3. Alterations and Additions
Alterations and additions to an existing dwelling which cost $50,000 ore more also require a BASIX certificate. A BASIX certificate can be obtained if you want to take precedence over your local council’s sustainability requirements even if your development is exempt from BASIX. This includes swimming pools and/or outdoor spas with water capacity greater than or equal to 40,000 litres or 40 kilolitres.
While the Assessment Tool for single dwellings and multi dwellings includes set reduction targets for water and energy use, the alterations and additions Assessment Tool does not have set targets.
How is the BASIX certificate assessed?
To assess the BASIX certificate, you can use the online Assessment Tool which will determine the sustainability of your development application. The assessment tool analyses data of the proposed dwelling’s design against the NSW Government’s water and energy targets. A BASIX certificate is issued upon meeting the BASIX target requirements and paying a fee.
When is it required to have more than one BASIX certificate?
Three instances may occur when it may be required to have more than one BASIX certificate. These are: the subdivision into single ‘Torrens title’ lots, development that involves strata title and for large multi-building residential flats.
Subdivision into single ‘Torrens title’ lots
When proposals include the subdivision of land into separate single dwellings that do not share property or services, the following options are available:
If only one BASIX certificate is required, the BASIX Multi-dwelling tool can be used to generate the certificate.
This tool reduces the total number of pages within the certificate by categorising the water, energy and thermal commitments for each dwelling into tables. If revisions occur to the application after the certificate is issued however, complications mat arise for both the applicant and the certificate issuer. If this occurs, single or grouped BASIX certificates provide greater flexibility for revisions to occur for individual dwellings.
Development involving strata title
A single BASIX certificate that covers the entire project application is required for the following developments:
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Residential buildings that are flat.
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Multi-dwelling houses.
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Villa units.
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Dual occupancy buildings.
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Multi-purpose used buildings on land that shares common property and shared services such as facilities.
Large multi-building residential flats
More than one BASIX certificate may be required for the following types of developments:
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Multiple residential ‘towers’.
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Blocks containing more than 100 units.
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Blocks containing more than 200 units for the overall development.
Having multiple BASIX certificates for these types of developments enables a quicker energy and water efficiency assessment as well as allowing revisions to be made to the project.
The BASIX tool allows up to 600 units/dwellings per certificate, over 600 the project will need to be divided into two separate BASIX certificates.
How is the BASIX certificate assessed?
To assess the BASIX certificate, you can use the online Assessment Tool which will determine the sustainability of your development application. The assessment tool analyses data of the proposed dwelling’s design against the NSW Government’s water and energy targets. A BASIX certificate is issued upon meeting the BASIX target requirements and paying a fee.
What do BASIX limitations include?
There are various circumstances where BASIX fails to meet the thermal modelling capabilities of NatHERS. BASIX specifies each component of a house individually whereas NatHERS does not. This makes using BASIX alone difficult as the ‘rapid method’ of assessment jumps to solutions such as expensive windows or shading devices, impacting costs and aesthetics. For example, BASIX may specify higher performance glazing and all that can be done to avoid this is to reduce the area of glazing. However, NatHERS has the ability to compensate elsewhere e.g. increasing insulation to avoid the expense of high performing windows. This makes the use of both BASIX and NatHERS much more cost effective in terms of construction as well as continual energy expenses.
Am I locked into my BASIX commitments once a construction or complying development certificate has been issued?
Yes. If the applicant wishes to change their BASIX commitments after a construction or complying development certificate has been issued, they will need to obtain a new BASIX Certificate and then apply for a new construction or complying development certificate.
What is the difference between a BASIX certificate and a NaTHERS Energy Rating?
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 and energy. 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.
Am I able to change my BASIX commitments after a construction or complying development certificate has been issued?
In order to change your BASIX certificate commitments after the construction or complying development certificate has been issued, you will need to revise your BASIX certificate in addition to applying for new construction or complying development certificates.