Residential Services

Our holistic approach to energy efficiency considers the environmental, economic and social impact of every project to offer clients and their community lasting livability.

Stellar Thermal approach all development projects with an intended outcome to protect and restore the environment whilst meeting the needs of present generations, without compromising future ones.

Whether a client’s vision is a vibrant communal lodge or a private residential sanctuary, we incorporate our design and construction insight to consistently deliver exceptional end-results. Discover more about our services below.

Sustainable Residential Development

In addition to contributing to the preservation of our planet, designing and building an eco-friendly home reduces the long-term costs of electricity, water and system maintenance.

NatHERS Thermal Performance Assessment

In addition to contributing to the preservation of our planet, designing and building an eco-friendly home reduces the long-term costs of electricity, water and system maintenance.

The Nationwide House Energy Rating Scheme (NatHERS) was initiated in 1993 by the Australian and New Zealand Minerals and Energy Council (later the Ministerial Council on Energy) to provide a standardised approach to rating the thermal performance of Australian homes.

NatHERS assessments are the most trusted way to meet the minimum residential energy efficiency requirements of the National Construction Code (NCC).

NatHERS uses a 10-point star system when rating a proposed new dwelling. On this scale, the higher the number, the more ‘thermally comfortable’ a home is, meaning less energy is required to heat and cool the property.

7 stars is the minimum rating acceptable for a new house in most states and territories and is considered to be an exceptional NatHERS rating.

A higher star rating reduces the year-round need for artificial heating or cooling to keep the climate of your home comfortable.

Please refer to the following video, or contact us for further information regarding NatHERS.

NatHERS Whole of Home

The NatHERS Whole of Home rating is in addition to the NatHERS Thermal Performance assessment and measures the energy use of the whole home including appliances, solar and batteries.

The Whole of Home rating is the largest upgrade to NatHERS over the past 30 years and will support important energy efficiency improvements for new homes across Australia. The new ‘whole of house’ assessment builds on the thermal performance assessment by providing information about the energy use of the following appliances: 

  • Heating and cooling
  • Hot water systems
  • Lighting
  • Pool/Spa pumps
  • Cooking and plug-in appliances
  • On-site energy generation and storage.

The rating considers energy used for heating, cooling, and appliances, minus energy generated from solar panels, building a useful energy snapshot of energy costs as well as greenhouse gas emissions.


Similar to the NatHERS Whole of Home protocol, the Building Sustainability Index (BASIX) 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 scheme aims to deliver equitable, effective water and greenhouse gas reductions across the state.

BASIX and the Planning System

An integrated part of the planning system, BASIX is implemented under the Environmental Planning and Assessment Act. BASIX applies to all residential dwelling types and is part of the development application process in NSW.

A Basix Certificate is required for:

  • New Houses
  • New Townhouses and Villas
  • New Dual Occupancies
  • New Granny Flats
  • New Flats and Apartments
  • Renovations of $50,000 or more to an existing home
  • Swimming pools and/or spas larger than 40,000 litres
  • The conversion of an existing non-residential building to a residential building.

A Basix Certificate is NOT required for:

  • Commercial or Industrial building works

BASIX Outcomes

A BASIX certificate assessment considers various criteria of the proposed development including:

  • Location
  • Orientation
  • Size of the building
  • Construction type of the building
  • Window size and placement
  • Landscaping including low water species.
  • Fixed Appliances

BASIX also considers the thermal performance rating of the proposed development which lessens the amount of energy used to heat or cool the dwelling to a comfortable level.

A BASIX certificate confirms that a proposed development complies with the NSW Government’s sustainability targets as well as the NCC2022 energy efficiency regulations.

Do I require a BASIX Certificate and a NatHERS Thermal Performance Assessment?

BASIX is a New South Wales government initiative designed to improve the environmental sustainability of residential developments.

BASIX currently sets out the minimum standards for compliance in the following three areas:

  • Water Efficiency
  • Thermal Performance / Comfort
  • Energy Efficiency

NatHERS is an Australian wide scheme that assesses the thermal performance of a proposed development’s building envelope. NatHERS assessments are the most trusted way to meet the minimum residential energy efficiency requirements of the National Construction Code (NCC).

The NatHERS thermal performance assessment rating is used within the ‘thermal performance section’ of the BASIX tool to show 7-star compliance.

New South Wales Compliance

In order to achieve the best thermal performance and energy efficiency result in NSW, we recommend using both BASIX and a NatHERS assessment tools.

Australia Wide Compliance (exc. NSW)

Although there are several pathways available to show compliance with the NCC2022 energy efficiency regulations, the most trusted method for a proposed new residential development is via a NatHERS Thermal Performance and Whole of Home Assessment.

Deemed to Satisfy (DTS) Provisional Energy Report

Residential Deemed to Satisfy (DtS) provisional energy report is a list of the minimum insulation values required by the National Construction Code (NCC) for ceilings / roofs, walls and floors, as well as the minimum thermal performance requirements for glazing and roof lights.


  • The Residential DtS is a prescriptive method which must be applied to your building regardless of any limitations your building may have.


  • The Residential Deemed to Satisfy (DtS) energy report does not provide information about the thermal performance (heating and cooling energy needs) of a home’s design, orientation and construction materials such as the wall, floor, roof / ceiling insulation and window glazing.


As the Deemed to Satisfy method is a prescriptive approach with no performance offsets permitted, it often limits options and budget conscious solutions for architects and their clients. 


VURB (Verification using a Reference Building Method) is an alternative assessment which provides more flexibility to meet energy efficiency requirements via a combination of both a NatHERS Thermal Performance assessment and the Deemed to Satisfy assessment (DTS).

VURB (Verification using a Reference Building Method) is an Energy Efficiency minimum performance standard that does not use an energy star rating like NatHERS, but a benchmark in the form of a reference building.


The proposed building must reach either the same or less than the Elemental Provisions (DTS) of the reference building’s benchmark energy heating/cooling loads to be compliant with the National Construction Code (NCC).


This report option is currently available for all States and Territories except New South Wales (refer to BASIX).

Please contact the team at Stellar Thermal for more information about your next residential development.