Building sustainability has become a central focus of Australia’s green policies. No wonder, builders and architects are looking for tools that can help them design sustainable buildings and meet the standards set by their localities. Two key tools playing a critical role in guiding sustainable designs are NatHERS (Nationwide House Energy Rating Scheme) and BASIX (Building Sustainability Index).

Whether you are designing a single building or dealing with a multi-unit project, you must understand these tools to use them properly. If you are confused, we will explain everything regarding NatHERS and BASIX below, so keep reading. 

What is NatHERS? 

NatHERS stands for Nationwide House Energy Rating Scheme. It is a federal initiative that uses thermal modelling software to estimate the energy efficiency of a residential building’s design, primarily regarding heating and cooling loads. Australia has introduced it to help builders and homeowners make their homes more comfortable and environmentally sustainable.

Source: MDPI 

Australia’s average land and sea temperatures have risen in recent decades, and the trend is expected to continue. It makes NatHERS and sustainable housing extremely important. 

What Does NatHERS Include? 

Since NatHERS is a detailed assessment, you need to chat with your builder and understand its various elements. 

NatHERS assessments account for the local climate and weather patterns, since it divides Australia into 69 climates zones. Here is what it considers:

1. Building Orientation 

NatHERS assesses how well your home takes advantage of its position relative to the sun. If your property faces north, it can capture more sunlight during winters, helping to naturally warm the home and reduce heating costs. Proper orientation also improves overall comfort and energy efficiency throughout the year. 

2. Insulation in Walls, Roofs, and Floors 

The scheme also evaluates the quality and placement of insulation in roofs, walls, and floors. Quality insulation acts as a barrier against heat loss in winter and heat gain in summer, making your home thermally efficient. 

3. Window Placement, Size, and Glazing 

Windows play a crucial role in your home’s energy performance. NatHERS considers their size, position, and type of glazing to ensure they allow in natural light and warmth without causing overheating or heat loss. The right window design can significantly improve the thermal comfort of a building. 

4. Ventilation and Shading 

Natural ventilation and strategic shading are key components of an energy-efficient home. NatHERS looks at how well your home allows for airflow to cool the interior naturally, and whether shading elements like eaves, pergolas, or blinds are used to block out unwanted summer heat. 

5. Construction Materials 

The materials used to build your home also impact its thermal performance. NatHERS reviews how well these materials absorb, store, and release heat. Choosing the right combination of materials can improve energy efficiency and help regulate indoor temperatures year-round. 

NatHERS gives a rating to a residential building that falls between 1 and 10, the higher the better:

• A 0-Star home offers no insulation or protection from external temperatures. 
• 7-Star rating, which is the national minimum requirement, represents satisfactory thermal performance. 
• 10-Star is the highest, which indicates that the home requires no artificial cooling or heating. 

These ratings are generated using accredited software like FirstRate5, AccuRate, BERS Pro, and must be performed by a NatHERS Accredited Assessor.

NatHERS Variations Between States and Territories  

The following are the regional variations of NatHERS in Australia:

• In Australian Capital Territory (ACT), Class 1 and 4 buildings must achieve a 7-Star rating. The Class 2 buildings should have an average of 7-Star, with each individual unit having a minimum not less than 6-Star rating. 
• BASIX is the standard tool in NSW, which is different from NatHERS. It is only used in NSW. 
• The buildings in Northern Territory (NT) should at least have a 6-Star rating. 
• Queensland (QLD), South Australia (SA), Tasmania (TAS), Victoria (VIC), and Western Australia (WA) have a minimum 7-Star energy rating requirements. 

What is BASIX? (Building Sustainability Index) 

BASIX is a New South Wales-specific sustainability planning tool managed by the NSW Government’s Department of Planning and Environment. It was developed to cut water consumption by 40% and reduce greenhouse gas emissions by 25%. Since its introduction in 2004, it has been mandatory for all new residential housing projects in NSW to obtain the BASIX certificate.

Today, BASIX is applicable to all residential dwellings that cost $50,000 or more. These include townhouses, hostels, swimming pools with water capacity greater than 40,000 litres, single dwellings, and the like. 

Here are the elements that BASIX focuses on:

• Water: Encourages reduced consumption through efficient fixtures, rainwater tanks, and landscaping 
• Energy: Reduced greenhouse gas emissions by promoting energy-efficient lighting, hot water systems, and renewable energy options like solar panels. 
• Thermal Comfort: Ensures homes maintain comfort year-round, using passive design principles or thermal simulation (via NatHERS). 

Every project must pass minimum performance targets in all three categories to receive a BASIX certificate. It is required for lodging a Development Application (DA) with the local council. 

When a BASIX Certificate Is Not Required 

Although obtaining a BASIX certificate is mandatory for most housing projects, the following types of developments may be exempt from BASIX assessment:

• Structures meant for temporary use 
• Alteration or renovation projects costing less than $50,000
• Some low-cost housing projects in NSW may be exempt or subject to reduced BASIX requirements. Renovating some Class 10 buildings with fences, swimming pools, sheds, and the like 

An Important Consideration 

NSW has made considerable changes to thermal performance standards and higher energy standards. They have also introduced a new standard for calculating the embodied emissions of building materials. These new standards apply to all residential buildings except those located in climate zones 9, 10, and 11 or are up to 5 storeys. 

NatHERS and BASIX – A Detailed Comparison 

Let PassivEnergy Handle NatHERS and BASIX 

If you have read to this point, you know NatHERS and BASIX assessments can be quite complicated. But that’s not the case if PassivEnergy is on your side and handling everything. Whether it is a 6-Star assessment, a 7-Star analysis report, or a detailed BASIX analysis, our team has the expertise and understanding to help you gain the required efficiency standards. 

We are well-versed in using BASIX, BESS, STORM, and other assessment tools. Our experts are at the forefront of the sustainability drive and stay updated on the latest technological shifts in this sector. 

You can contact us today, and we’ll handle the rest with expertise.