We look at each state and find out what is required of owners and Builders Melbourne and Draftsperson.

New South Wales

The NSW program is the Building Sustainability Index, or BASIX. BASIX is an online tool which calculates the energy and water efficiency of a new home design. You need to get a BASIX Certificate to get planning approval for your home Sustainable house design.

The questions relate to:

The size of the house and its orientation
The building materials to be used
Whether a rainwater tank will be installed
Water fittings, including taps, toilets and showerheads
How many windows and where they are in relation to the sun
Choice of hot water system
How the house will be kept warm and cool with insulation

The BASIX tool then evaluates your answers and provides scores. In order to get a BASIX certificate your house must:

Score 25 or more for energy
Score 40 or more for water*
Achieve a pass for thermal comfort
* The BASIX water target varies across the state, depending on the climate. The eastern areas have a water target of 40.

BASIX is flexible in that there are a few ways you can achieve the target. For example, you may not always need to have a rainwater tank to get your water target; in some areas installing AAA plus showerheads, toilets and tap fittings will be enough to get you over the line.

BASIX was introduced for single dwellings and dual occupancies in the Sydney area on 1 July 2004, the rest of NSW on 1 July 2005 and for all residential dwellings including low- and high-rise apartments on 1 October 2005.

In July 2006, BASIX became a requirement of all residential additions and alterations in NSW, and the energy target was increased to 40.


The Victorian program is called 5 Star, and stipulates, unsurprisingly, a 5 star energy requirement for all new homes.

In addition to achieving this rating for the building fabric, 5 Star also requires either a water tank that must supply water to all toilet cisterns, or a solar hot water system. Where there is reticulated gas the solar hot water system must be gas boosted.

5 Star was implemented on July 1, 2004. For the first 12 months a transitional period existed where 4 Stars for the fabric could be achieved with the addition of either a water tank or a solar hot water system.

This transitional period has been extended until April 30, 2006 for homes with a suspended timber floor or of earthwall construction.

The 5 Star verification method requires the design to be assessed by a person accredited in the use of energy rating software. The approved programs for Victoria are FirstRate and NatHERS. The energy report will form part of the required documentation for building permit approval. As an alternative to using software packages, in the case of the 4 Star plus option, the Building Code of Australia (BCA) energy efficiency provisions can be used.

For apartments, an average 5 Star rating is required for the whole building and each sole occupancy dwelling must achieve a rating of at least 3 Stars. There is no requirement to install a water tank or solar hot water system in an apartment building.

As well as the energy provisions there are water conservation requirements for Victoria through the plumbing regulations. The regulations require pressure reduction that will restrict water pressure to a building and also flow restriction to shower heads and taps.

There is some discussion about a move to 6 Star, but nothing has been agreed on as yet.

Australian Capital Territory

The ACT’s program is called ACTHERS, and is based on NatHERS. The minimum rating is 4 stars, assessed using FirstRate, and is based on these design factors:

Air leakage
Design features
Floor type
Thermal mass
Width of eaves
Cross ventilation
Common walls
If the rating is acceptable, an Energy Efficiency Rating Statement (EER) is issued.

Importantly, a valid EER is required for new house designs as well as the sale of an existing house.

In line with changes to the BCA, the ACT will move to a 5 star minimum for all residential designs on May 1, 2006. The ACT Government is also considering adopting the NSW BASIX system, although this is unlikely to occur until late 2006 at the earliest.

The BCA states

Queensland, South Australia, Western Australia, Tasmania and the Northern Territory use the Building Code of Australia’s energy efficiency provisions, which came into effect on January 1, 2003 (September 1, 2003 in Queensland).

The BCA calls for a minimum energy rating for new houses of 4 stars, which is based solely on the design and construction materials used in a new home. This includes requirements for:

Roof and wall insulation
Eaves and other shading
Glazing and high performing windows
Natural ventilation
The BCA allows for assessment either through a ‘deemed to satisfy’ method which specifies the construction materials needed to achieve the home’s energy efficiency rating. Otherwise computer software such as FirstRate and NatHERS can be used. These give more flexibility in mixing materials and design options.

Some states have slight variations in the deemed to satisfy requirements, while others are looking at adopting their own programs which rate energy and water, such as BASIX.

Although the above states have developed stricter regulations beyond the BCA, all states are represented on the Australian Building Codes Board (ABCB), which manages the BCA.

This means that the ABCB is looking at revamping energy efficiency regulations to become stricter and standard across Australia.

In 2006, the proposed changes to the BCA will increase the energy efficiency requirements for homes to 5 stars, but the changeover date hasn’t been finalised.


Queensland’s Sustainable Housing initiative has proposed additional requirements beyond the BCA. These new requirements will require all new houses to have:

Greenhouse-efficient hot water systems
Energy efficient lighting
AAA-rated shower roses
Dual-flush toilets
Water pressure-limiting devices
Rainwater tanks (not required by all councils)
In units and apartments, the standard will require:

Energy efficient lighting
AAA-rated shower roses
Dual-flush toilets
The standard also affects bathroom renovations, requiring:

AAA-rated shower roses
Dual-flush toilets
The new standard will come into effect on 1 March, 2006 with a second stage of changes opening for discussion some time after that.

South Australia

South Australia has no plans to develop their own standard, so will be sticking with the BCA. However, the SA Housing Code also regulates sealing capacity, air movement, hot water services, and where external glazing and/or shading is required.

Furthermore, roofs, external walls and suspended floors must achieve a minimum total thermal resistance.

The most common form of appraisal for builders in South Australia is the BCA’s deemed to satisfy.

The 4 star minimum is to become a 5 star minimum on July 1, 2006, and from that date all new homes and homes undergoing major renovation must have a plumbed rainwater tank. Tanks must be 1000 litres and plumbed into a toilet or laundry.

Western Australia

Although it is looking at BASIX, Western Australia will probably stick with the BCA and its more stringent guidelines next year.

In terms of water efficiency, dual flush toilets have been mandatory for a number of years through the state’s plumbing regulations.

For approvals, WA is reviewing AccuRate, the successor to NatHERS.

In 2006, the proposed changes to the BCA will increase the energy efficiency requirements for homes to 5 stars, but the changeover date hasn’t been finalised.


Tasmania has no plans to move away from the BCA. For assessment, Tasmania uses only the deemed to satisfy method and does not provide the option of using a computer generated model to assess the design.

DTC allows the builder to submit a design that meets a set of minimum criteria. The assessor will ask questions such as ‘Does it have insulation of 3.5 in the roof?’, ‘Does it have insulation of 0.5 in the walls?” and ‘Does it have insulation of hot water pipes?’.

Northern Territory

The Northern Territory government is contemplating the adoption of the BCA 2006 5 star energy efficiency requirements. If adopted, the NT government is undecided as to what method of assessment they will use but currently the preference is for deemed to satisfy BCA provisions.

This is primarily a result of the difficulties that were experienced in applying the NatHERS computer model in tropical Australia due to an issue with natural ventilation in the tropics. The updated version of the NatHERS model, AccuRate, is currently undergoing practical testing.

*article by curtis cooper from realestate.com.au 15.03.2010