NSW Residential Sustainability Comparison
Green Star Homes and BASIX can both influence the sustainability of a new home in New South Wales, but they serve different purposes, apply to different project structures and produce different forms of evidence and recognition.
BASIX is a New South Wales residential sustainability assessment used within the planning and development approval pathway. Where it applies, the project must complete the relevant assessment and carry the resulting certificate commitments into the design and construction documentation.
Green Star Homes is a separate voluntary certification framework administered by the Green Building Council of Australia. It is structured for eligible volume home builders delivering repeatable home designs or residential product ranges.
A NSW home may therefore require BASIX regardless of whether Green Star Homes certification is being pursued. The two pathways can be coordinated, but neither replaces the other. For full pathway guidance, visit the Green Star Homes Knowledge Hub and the BASIX assessment page.
In Brief
A NSW Approval Requirement and a Voluntary Certification Framework
BASIX
A NSW assessment addressing water, energy and thermal performance within the residential planning and approval process.
Green Star Homes
A voluntary GBCA certification pathway for eligible volume home builders covering Positive, Healthy and Resilient outcomes.
Core Difference
BASIX establishes project-specific NSW commitments. Green Star Homes coordinates a wider builder, product-range and completed-home certification pathway.
A project may use BASIX, NatHERS, Whole of Home and Green Star Homes at the same time, but each assessment retains its own purpose, method and evidence requirements.
Comparison at a Glance
Green Star Homes vs BASIX: The Main Differences
NSW Residential Approval
BASIX
Residential Sustainability Certification
Green Star Homes
NSW Planning Context
What Is BASIX Designed to Do?
BASIX stands for the Building Sustainability Index. It forms part of the New South Wales development assessment framework and applies to all new residential dwellings together with certain alterations, additions, pools and spas.
Alterations and additions valued at $50,000 or more, and pools or spas with a combined capacity of 40,000 litres or more, generally enter the BASIX pathway. The correct assessment type and any applicable exemptions should still be confirmed for the specific development.
The BASIX tool uses project information to assess water use, energy use and thermal performance. It also estimates embodied emissions associated with nominated building materials under the current materials component.
Once the assessment satisfies the applicable standards, the BASIX Certificate records the commitments relied upon by the project. Those commitments must remain aligned with the approval documentation and the work ultimately constructed.
Voluntary Certification Context
What Is Green Star Homes Designed to Do?
Green Star Homes is administered by the Green Building Council of Australia and is created for eligible volume home builders. It is intended to support repeatable delivery of highly efficient, fossil fuel free, renewable-powered, healthy and resilient homes.
The framework is organised around Positive, Healthy and Resilient outcomes. These outcomes bring energy performance together with indoor-environment, water, climate-readiness and delivery requirements that extend beyond the BASIX approval scope.
Green Star Homes also operates at more than one delivery level. The builder’s eligible designs or product range are assessed through the applicable design pathway, while individual completed homes require evidence showing that the assessed measures were delivered.
This makes Green Star Homes a certification framework rather than an alternative residential planning certificate.
Eligibility Boundary
Eligibility Is a Defining Difference
BASIX applicability is determined by the location, development type and NSW approval pathway. The project does not need to be delivered by a volume builder for BASIX to apply.
Green Star Homes uses a different entry model. The current pathway is structured around eligible volume home builders, repeatable residential designs, controlled specifications and delivery processes that can be applied across multiple homes.
A bespoke dwelling, renovation or smaller residential development may therefore require BASIX while falling outside the current Green Star Homes volume-builder pathway.
A project should establish Green Star Homes eligibility before treating the framework as part of its certification strategy.
Approval Boundary
Does Green Star Homes Replace BASIX?
No. A NSW residential development must still complete BASIX where the framework applies. Voluntary certification does not remove the statutory planning and development approval requirements.
The reverse is also true. Achieving the applicable BASIX standards does not make the dwelling a certified Green Star Home. BASIX does not assess Green Star Homes eligibility or complete the separate GBCA certification process.
A project can pursue both pathways because they perform different functions. BASIX supports approval of the NSW development. Green Star Homes supports voluntary recognition of a wider sustainability outcome.
The project team should therefore coordinate the information while keeping the certificate, submission and decision-making boundaries clear.
Shared Project Information
Where Do Green Star Homes and BASIX Overlap?
Thermal Performance
Fabric and Climate Response
Orientation, layout, glazing, shading, insulation and construction information can influence both BASIX thermal commitments and Green Star Homes energy outcomes.
Household Energy
Services and Fuel Sources
Hot water, heating, cooling, ventilation, cooking and other systems can affect BASIX energy performance and the Green Star Homes Positive strategy.
Water Demand
Fixtures and Appliances
Showers, taps, toilets, appliances and other water-using products may be represented in both the BASIX water assessment and Green Star Homes evidence.
Alternative Water
Rainwater Systems
Tank capacity, roof catchment and nominated reuse may support both pathways where the physical system and required evidence remain aligned.
Renewable Energy
Solar and Storage
Onsite generation and battery information may influence residential energy results and support a broader renewable-powered home strategy.
Documentation
Plans and Specifications
Both pathways depend on project information that accurately represents the design, selected systems and products intended for construction.
This overlap can reduce duplicated design effort. It does not mean that one certificate, model or product schedule will automatically satisfy both assessment systems.
Broader Certification Scope
Where Does Green Star Homes Extend Beyond BASIX?
BASIX is focused on the sustainability standards and commitments required for the NSW residential approval. Green Star Homes uses a broader certification structure and evaluates matters outside that approval purpose.
Positive outcomes. Highly efficient, fossil fuel free homes powered by renewable energy.
Healthy outcomes. Indoor air quality, ventilation, moisture, thermal conditions and relevant product requirements.
Resilient outcomes. Water efficiency, extreme heat, climate readiness and relevant natural hazards.
Product-range controls. Standard designs, specifications, options and substitution procedures applied across multiple homes.
Completed-home certification. Project-specific evidence confirming that the assessed measures were delivered in an individual dwelling.
Supporting Energy Assessments
How Do NatHERS and Whole of Home Fit Into the Comparison?
NatHERS and Whole of Home should remain distinct from both BASIX and Green Star Homes, even where their results contribute useful technical information.
NatHERS Thermal Rating
Dwelling Fabric Performance
Models heating and cooling demand using the climate, orientation, layout, glazing, shading, insulation and construction represented in the assessment.
Whole of Home
Household Energy Systems
Considers major household systems together with onsite solar generation and battery storage where applicable.
These assessments may inform BASIX documentation and Green Star Homes strategy in different ways. They do not replace either framework.
For a detailed boundary between the energy rating and certification pathways, see Green Star Homes vs NatHERS.
Supporting Project Information
How Can BASIX Information Support Green Star Homes?
For an eligible volume builder operating in NSW, BASIX can establish project information that may also be relevant to parts of the Green Star Homes submission.
This may include NatHERS assumptions, glazing and insulation specifications, water fixtures, rainwater systems, hot-water equipment, heating and cooling, solar generation and materials information.
The existence of that information does not confirm that it is sufficient for certification. Green Star Homes may require different calculations, product details, builder-level procedures or completed-home records.
The useful question is therefore not whether BASIX can be reused in full, but which documented assumptions can support the separate Green Star Homes evidence pathway.
Assessment and Evidence
How Do the Evidence Pathways Differ?
BASIX is completed for the applicable NSW development. The assessment uses project-specific inputs and produces a certificate containing commitments that must be reflected in the development documentation.
Green Star Homes begins with the eligible builder’s designs, specifications and delivery processes. The design or product-range assessment establishes the controlled basis from which individual homes can proceed.
Individual completed homes then require evidence appropriate to the certification pathway. This may include schedules, certificates, invoices, photographs, commissioning records and other construction information.
A BASIX Certificate can establish relevant project commitments, but it is not completed-home Green Star Homes evidence by itself.
Document Coordination
Why Must the Project Information Remain Aligned?
Where both pathways are being pursued, the BASIX Certificate, NatHERS documentation, architectural drawings, product schedules and Green Star Homes submission should describe the same dwelling.
Control glazing and façade options. Window changes can affect thermal modelling, BASIX commitments and Green Star Homes evidence.
Keep construction specifications consistent. Insulation and building systems should match across ratings, drawings, schedules and procurement.
Review services substitutions. Changes to hot water, heating, cooling, cooking or solar systems may affect more than one assessment.
Preserve water commitments. Fixture ratings, tank capacity, catchments and reuse connections should remain coordinated.
Collect construction records. Installed products and systems should remain identifiable for approval and certification evidence.
Project Decision
Which Pathway May Be Relevant?
BASIX Only
The NSW project requires its applicable planning and sustainability assessment but is not pursuing Green Star Homes certification.
Green Star Homes Only
An eligible volume builder is delivering homes outside NSW or where BASIX is not part of the applicable jurisdictional pathway.
Combined NSW Pathway
An eligible NSW volume builder needs project-specific BASIX approval work alongside the wider Green Star Homes product-range strategy.
Alternative Pathway
A custom dwelling, apartment development or other residential project may need BASIX while requiring a different voluntary performance or certification framework.
Common Misunderstandings
What Should the Two Pathways Not Be Confused With?
BASIX is not Green Star Homes certification. It belongs to the NSW planning and approval framework.
Green Star Homes is not an alternative to BASIX. Voluntary certification does not remove NSW approval requirements.
Green Star Homes is not available to every new dwelling. The current framework is structured for eligible volume home builders.
Shared subject matter does not mean shared evidence. The same product or system may require different documentation under each pathway.
Green Star Designed is not final home certification. The individual completed dwelling still requires its applicable evidence review.
A certificate does not eliminate document control. Design changes and substitutions may require both assessments to be reviewed.
Frequently Asked Questions
Green Star Homes vs BASIX FAQs
Is Green Star Homes the same as BASIX?
No. BASIX is a NSW residential sustainability assessment used within the planning and approval pathway. Green Star Homes is a separate voluntary GBCA certification framework for eligible volume home builders.
Does Green Star Homes replace BASIX in NSW?
No. A NSW residential project must still complete BASIX where it applies. Green Star Homes certification does not remove the applicable planning and development approval requirements.
What does BASIX assess?
The core BASIX assessment addresses water use, energy use and thermal performance. The current tool also estimates and records embodied emissions associated with nominated building materials.
Which projects require BASIX?
BASIX applies to all new residential dwellings in NSW and to applicable alterations and additions valued at $50,000 or more, together with pools or spas of 40,000 litres or more. The project-specific pathway and any exemptions should be confirmed.
Who can pursue Green Star Homes?
The current Green Star Homes framework is created for eligible volume home builders delivering repeatable residential designs or product ranges. Eligibility should be confirmed against current GBCA guidance.
Can BASIX information support Green Star Homes?
Potentially. BASIX, NatHERS and Whole of Home information may support related water, thermal and energy requirements, but Green Star Homes retains its own framework and evidence obligations.
Does a BASIX Certificate make a home Green Star certified?
No. Formal Green Star Homes certification requires the applicable GBCA assessment and completed-home evidence pathway.
Is Green Star Designed final certification?
No. The design or product-range assessment must be followed by the applicable review of the completed individual dwelling before certification is confirmed.
Can a one-off custom home use Green Star Homes?
A one-off custom home should not assume eligibility. The current Green Star Homes model is structured around eligible volume home builders and repeatable product ranges.
When should BASIX and Green Star Homes be coordinated?
Coordination should begin while standard designs, glazing, insulation, water systems, household services and customer-selection processes can still be adjusted. Early alignment reduces conflicting documentation and late design changes.
Related Guidance
Explore the Connected Residential Pathways
Last reviewed: June 2026. BASIX is administered through the NSW Government planning framework. Green Star Homes is administered by the Green Building Council of Australia. Current applicability, eligibility, assessment and submission requirements should be confirmed against the relevant official guidance.
NSW Residential Pathway Review
Need to Coordinate BASIX and Green Star Homes?
Send the available plans, product-range information, standard specifications and certification objectives for an initial review. Certified Energy can help clarify the NSW BASIX pathway and how its technical inputs may support the wider Green Star Homes certification strategy.
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