BASIX Certificate NSW: Complete Guide to Requirements, Cost and the Online Assessment Process
BASIX (Building Sustainability Index) is the NSW Government’s mandatory sustainability assessment for new residential buildings and major renovations. Every Development Application or Complying Development Certificate for a new home, townhouse, apartment building or significant renovation in NSW must be accompanied by a BASIX certificate before approval can be granted.
This guide explains what BASIX is, what a BASIX certificate covers, how the online assessment process works, what it costs, the 7-star NatHERS thermal requirement introduced in October 2023, and when you need a BASIX consultant. It is written for homeowners, architects, builders and developers working on residential projects anywhere in New South Wales
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Table of Contents
- 01What Is BASIX? Definition and Purpose
- 02What Is a BASIX Certificate?
- 03BASIX Requirements - What Must Your Home Meet?
- 04BASIX Assessment Process - Step by Step
- 05BASIX Certificate Cost
- 06BASIX NSW - Jurisdiction and Regulatory Framework
- 077-Star BASIX Requirements Explained
- 08BASIX for Sydney and Regional NSW
- 09BASIX Consultant - Why Use One?
- 10BASIX Certificate Requirements - Compliance Through Construction
- 11Torple's BASIX Assessment Service - What to Expect
- 12BASIX Frequently Asked Questions
What Is BASIX? Definition and Purpose
BASIX stands for Building Sustainability Index. It is a NSW Government initiative first introduced
in 2004 under the original BASIX State Environmental Planning Policy. Since 1 October 2023,
BASIX has been governed by the State Environmental Planning Policy (Sustainable Buildings)
2022, which replaced the former BASIX SEPP 2004 as the legal basis for the scheme.
When compliance requirements seem complex, partnering with a qualified Residential Energy
Consultant or specialist BASIX Energy Consultant ensures your project stays on track from day
one.
BASIX is mandatory for all new residential buildings and major renovations in NSW. It applies
before a Development Application (DA) or Complying Development Certificate (CDC) can be
approved, and it sets binding sustainability targets across three areas: water efficiency, energy
use, and thermal comfort.
What is BASIX?
BASIX (Building Sustainability Index) is a NSW Government mandatory sustainability
assessment that all new residential buildings and major renovations must pass before
receiving development approval. It sets binding targets across three areas: water efficiency,
energy use, and thermal comfort (assessed via NatHERS star rating).
To understand how this assessment is documented, see what a BASIX certificate is below – the
formal compliance document generated once a project meets all three BASIX targets.
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What Is a BASIX Certificate?
A BASIX certificate is the formal compliance document issued by the NSW Planning Portal confirming that a proposed residential development meets the BASIX sustainability targets. It is required to accompany every Development Application or Complying Development Certificate for a new home or major renovation anywhere in NSW.
BASIX Compliance Certificate vs BASIX Certificate
These two terms are used interchangeably in industry conversation, but there is only one document: the BASIX certificate. It is issued after the applicant completes the online BASIX assessment via the NSW Planning Portal BASIX tool, and only once all three targets – water, energy, and thermal comfort – have been met.
No council and no private certifier issues the BASIX certificate. It is self-generated through the online tool, subject to the commitments the applicant agrees to honour throughout construction.Those commitments – fixture types, insulation levels, hot water systems, and so on – are what the building certifier later verifies on site.
What Triggers the Need for a BASIX Certificate
- New dwellings – Class 1 houses, townhouses, duplexes, and secondary dwellings (granny flats)
- Class 2 apartment buildings – buildings up to 5 storeys; specific provisions apply for taller buildings
- Swimming pools with a volume over 40,000 litres
- Alterations and additions with a cost of works of $50,000 or more
BASIX Certificate Validity
A BASIX certificate is valid for 3 months from its date of issue. If the DA or CDC is not lodged within that 3-month window, the certificate expires and a new one must be generated through the BASIX tool before lodgement can proceed.
Regulatory context – Sustainable Buildings SEPP 2022
Since 1 October 2023, the former BASIX SEPP 2004 has been replaced by the State Environmental Planning Policy (Sustainable Buildings) 2022. This is the current legal basis for BASIX certification in NSW.
See the State Environmental Planning Policy (Sustainable Buildings) 2022 for the full current
legal basis governing BASIX.
BASIX Requirements - What Must Your Home Meet?
Every BASIX assessment tests a proposed home against three mandatory targets. The table below summarises what each target measures, the benchmark a home must meet, and how compliance is assessed.
| Target | What Is Assessed | Benchmark / Threshold | Assessment Method |
|---|---|---|---|
| Water | Potable water consumption - fixtures, irrigation, pool | Up to 40% reduction vs pre-BASIX benchmark; target varies by LGA and home type | BASIX online tool - self-assessed fixture ratings and rainwater system |
| Energy | Greenhouse gas emissions from heating, cooling, hot water, lighting, appliances | Up to 50% reduction vs benchmark; varies by climate zone and home type; measured in CO₂e | BASIX online tool - appliance and system selection inputs |
| Thermal Comfort | Heating and cooling loads - how well the building envelope maintains temperature | Minimum 7 NatHERS stars per dwelling (since 1 October 2023); or BASIX DIY path for eligible simple designs | NatHERS-accredited simulation software (FirstRate5, AccuRate, BERS Pro) or BASIX DIY method |
BASIX 7 Requirements NSW - Clearing Up a Common Search Term
‘BASIX 7 requirements NSW’ is a colloquial industry reference, not an official BASIX category. It refers to the seven data categories now collected in the updated BASIX tool: energy, water, thermal comfort, glazing, construction materials, embodied emissions (introduced October 2023), and appliances. This is distinct from the 7-star NatHERS rating, which is the specific thermal comfort sub-target within the energy and thermal comfort assessment.
If you are searching for the 7-star thermal requirement specifically, see the full explanation in the 7-Star BASIX Requirements section below.
Further detail on how these standards apply is available from the NSW Planning Portal – How BASIX standards apply.
The thermal comfort target sits within the broader national energy efficiency framework set by the ABCB NCC 2022.
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BASIX Assessment Process - Step by Step
The BASIX assessment is completed entirely online through the BASIX tool, now integrated into the NSW Planning Portal (planningportal.nsw.gov.au). Applicants must have a NSW Planning Portal account – applicant or developer role – to access the BASIX tool and generate a certificate. Architects, consultants, and builders can act on behalf of the applicant where delegated access is granted.
BASIX login – what changed in October 2023
The BASIX tool is accessed via your NSW Planning Portal login, not a separate basix.nsw.gov.au account as was the case prior to October 2023. The legacy BASIX portal has been migrated. Existing certificates created after 28 March 2009 remain accessible from the BASIX historical work dashboard.
The BASIX Assessment - 7 Steps
01 Create or log in to your NSW Planning Portal account
Access via planningportal.nsw.gov.au. Select applicant or developer account type. Consultants and architects acting on behalf of a client may be delegated access.
02 Start a new BASIX application
Select ‘Create BASIX Certificate’ from the Active Work dashboard. Enter the project address, LGA, lot and DP number, and select the development type (new dwelling, alteration/addition, swimming pool, etc.).
03 Enter project details
Floor area, number of bedrooms, glazing area, orientation, and climate zone (auto-populated from address). The tool uses your LGA to set the applicable water and energy targets.
04 Complete water target inputs
Specify all fixtures (shower heads, toilets, kitchen and bathroom taps), irrigation system, pool (if applicable), and alternative water system (rainwater tank). The tool calculates whether the water reduction target is
met.
05 Complete energy target inputs
Specify space heating and cooling systems, hot water system (heat pump, solar, gas, electric), lighting type, cooking appliance, and any on-site renewable energy (solar PV). The tool calculates projected greenhouse gas emissions.
06 Complete the thermal comfort section
Use the DIY method for eligible simple buildings, or upload NatHERS star rating results from an accredited assessor. Since October 2023, the minimum is 7 NatHERS stars.This is the step where most applicants partner with professional BASIX Consultants NSW to navigate thermal simulation requirements efficiently.
07 Pass all three targets and generate the certificate
Once water, energy, and thermal comfort targets are all met, the BASIX tool generates the certificate PDF, listing every commitment the applicant must honour during construction. It is then uploaded to the DA or CDC application.
The online assessment itself is completed via the BASIX tool, accessed through your NSW
Planning Portal account.
The enhanced BASIX tool
The enhanced BASIX tool launched 1 October 2023. All new applications use the tool via the NSW Planning Portal. The legacy standalone basix.nsw.gov.au system is no longer used for new applications.
BASIX Certificate Cost
A BASIX certificate has two cost components: the government processing fee charged by the NSW Planning Portal, and – for most projects – the fee charged by a NatHERS-accredited consultant to complete the thermal comfort assessment.
1. NSW Planning Portal Fee
The BASIX tool charges a government processing fee per certificate, set out by the NSW Planning Portal. The maximum fee is $50 for a single dwelling, $80 for the first two dwellings in a multi-dwelling development, and $35 for each additional dwelling beyond that. Projects requiring a NatHERS thermal simulation attract a further $30 NatHERS certificate fee. These fees are subject to periodic CPI adjustment – confirm the current amount at planningportal.nsw.gov.au at the time of lodgement.
2. Consultant Fee (NatHERS Assessment)
The thermal comfort section of BASIX requires a NatHERS-accredited assessor for most residential projects. Assessor fees typically range from $250 to $600 for a standard house, depending on floor area and design complexity. Larger homes, duplexes, and multi-dwelling projects cost more. Alteration and addition assessments are generally lower, reflecting the smaller scope of the thermal model.
Factors That Affect BASIX Certificate Cost
- Project type – new dwelling, alteration/addition, duplex, or apartment
- Floor area and number of dwellings being assessed
- NatHERS modelling complexity – orientation, glazing, non-standard design
- Whether the project requires revision rounds – for example, design changes after the initial assessment
- Urgency – an expedited NatHERS assessment may attract a premium
How much does a BASIX certificate cost?
A BASIX certificate involves a NSW Planning Portal processing fee of $50 for a single dwelling (up to $80 for the first two dwellings of a multi-dwelling project, plus $35 per additional dwelling, and a further $30 where a NatHERS certificate is required), plus a NatHERS assessor fee typically ranging from $250 to $600 for a standard house. Total cost depends on project complexity, floor area, and the number of dwellings being assessed.
To streamline your project, trust our accredited BASIX Assessment Services for a reliable,
Fast BASIX Certificate turnaround.
BASIX NSW - Jurisdiction and Regulatory Framework
BASIX applies exclusively in New South Wales, administered through the NSW Planning Portal. Other Australian states and territories use different sustainability frameworks: Victoria uses NatHERS together with FirstRate5 or AccuRate for residential thermal performance, and Queensland, South Australia, and other jurisdictions also rely on NatHERS under the National Construction Code rather than a state-specific scheme like BASIX. BASIX is not applicable outside NSW. If your project is located anywhere in NSW, BASIX is mandatory – regardless of whether the project is in metropolitan Sydney or regional NSW.
Regulatory Basis
From 1 October 2023, BASIX is governed by the State Environmental Planning Policy (Sustainable Buildings) 2022, which replaced the former BASIX SEPP 2004. The scheme is administered by the NSW Department of Planning and Environment, with the NSW Environment Protection Authority involved in setting underlying sustainability benchmarks.
BASIX Report vs BASIX Certificate - What Is a BASIX Report?
A BASIX report and a BASIX certificate are distinct documents, and the difference matters for anyone managing a DA submission. The BASIX report is the summary of assessment inputs and results – it records what was entered into the BASIX tool, the calculated performance against each target, and the commitments made. The BASIX certificate is the formal compliance document generated once all three targets are passed. Both documents are attached to the DA or CDC application. Assessors will also typically produce a separate NatHERS report covering the thermal comfort section, which is uploaded alongside the BASIX certificate as supporting evidence.
Post-Consent BASIX Obligations
Commitments made in the BASIX certificate must be carried through into construction. A BASIX completion receipt – formerly known as the BASIX compliance certificate – is required at the Occupation Certificate (OC) stage. It is issued by the private certifier after they verify that all BASIX commitments have been fulfilled on site.
7-Star BASIX Requirements Explained
The 7-star requirement in BASIX refers to the minimum NatHERS (Nationwide House Energy Rating Scheme) thermal performance rating a dwelling must achieve. Since 1 October 2023, all new dwellings in NSW subject to BASIX must achieve a minimum of 7 NatHERS stars for the thermal comfort target. This replaces the previous average of 5.5 to 6 stars required under the former BASIX SEPP 2004.
What is 7-star BASIX?
Since 1 October 2023, the BASIX thermal comfort target requires a minimum of 7 NatHERS stars per dwelling in NSW, replacing the previous 5.5–6 star average required under the former BASIX SEPP 2004. The rating measures how well the building envelope maintains a comfortable indoor temperature without relying on mechanical heating and cooling.
NatHERS Star Rating Explained
NatHERS rates the thermal shell of a building – how well the design maintains a comfortable internal temperature without relying on mechanical heating and cooling. It is rated on a 0 to 10 star scale, with 7 stars representing a significant step up from the previous standard: homes at this level require meaningfully less energy for heating and cooling year-round. Full detail on the national framework is available from NatHERS – National Administrator. The rating is assessed using NatHERS-accredited simulation software – FirstRate5, AccuRate Sustainability, or BERS Pro – by an accredited NatHERS assessor.
DIY Method vs NatHERS Simulation
The BASIX tool offers a DIY thermal comfort pathway for simple, eligible buildings – typically single-storey, rectangular homes with limited glazing. Most projects, however, require a full NatHERS simulation by an accredited assessor. Torple’s assessors hold NatHERS accreditation and can advise at the briefing stage which pathway applies to a given project.
Design Implications of the 7-Star Target
- Orientation matters more – north-facing living areas and optimal window placement are now critical to achieving 7 stars
- Insulation specifications must be higher – ceiling, wall, and floor R-values are typically more demanding than pre-2023 designs
- Glazing performance must be carefully managed – SHGC and U-values matter;excessive east or west-facing glazing penalises thermal performance
- Shading is often required – eaves, external blinds, or louvres for west-facing glazing are frequently necessary to maintain 7 stars
- Building sealing complements the target – draught sealing requirements under NCC 2022 work alongside the 7-star thermal target
Achieving these stringent targets often requires expert guidance from a certified Energy Efficiency Consultant to optimize glazing, insulation, and orientation without compromising your
architectural vision.
These thermal sealing and envelope provisions are set out in the ABCB NCC 2022, whichcomplements the BASIX thermal comfort target.
Struggling to Hit the Mandatory 7-Star NatHERS Target?
Architectural changes can easily disrupt your thermal compliance. Talk to our BASIX energy consultants early to optimize your glazing, insulation, and shading parameters seamlessly.
A note on precision
‘7 star BASIX’ is commonly used in industry conversation, but technically BASIX sets the 7-star NatHERS thermal comfort target as one of its three assessment areas – the star rating itself is a NatHERS output, not a BASIX-specific scale. The precise statement is: BASIX requires 7 NatHERS stars, not ‘7 BASIX stars’.
BASIX for Sydney and Regional NSW
BASIX applies identically across every part of NSW, but the specific energy and thermal comfort targets a home must meet are shaped by climate zone – which varies significantly across the state.
BASIX Sydney
Torple delivers premium BASIX Assessment Sydney services for all Sydney metropolitan local government areas- including the Inner West, Northern Beaches, Eastern Suburbs, Western Sydney, South Western Sydney, the Hills District, Sutherland Shire, and the outer suburban growth corridors. Greater Sydney spans multiple climate zones, primarily Climate Zone 6 (Sydney coastal) and Climate Zone 7 (inner and outer western Sydney). Climate zone affects both the energy and thermal comfort targets – the BASIX tool auto-populates the applicable zone directly from the project address.
BASIX Certificate Newcastle
Newcastle and the Hunter region fall within Climate Zone 5 and 6. BASIX applies identically to metro Sydney here – the same tool, the same three targets, and the same 7-star NatHERS requirement that has applied since 1 October 2023. Torple provides BASIX assessments across Newcastle, Lake Macquarie, Maitland, Port Stephens, and the broader Hunter Valley region.
Regional NSW
BASIX applies across all of NSW, including regional, rural, and coastal areas – there is no exemption based on location. Climate zones vary considerably across the state, ranging from Climate Zone 1 (hot humid north) to Climate Zone 8 (alpine). Targets adjust by zone, with more demanding thermal requirements applying in cooler inland and alpine zones. Torple serves all NSW postcodes.
BASIX Consultant - Why Use One?
Two terms are frequently confused in BASIX conversations: BASIX consultant and BASIX certifier. They refer to entirely different roles.
BASIX Consultant vs BASIX Certifier - The Key Distinction
A BASIX consultant – sometimes called a BASIX consulting firm – is an accredited energy assessor who prepares the NatHERS thermal assessment and assists with completing the BASIX tool inputs. A BASIX certifier is not a separate licence category at all – the term refers to a private building certifier who verifies that BASIX commitments have been fulfilled at the construction and Occupation Certificate stage. These are distinct roles performed by different professionals. Torple operates as a premier BASIX consulting partner, delivering comprehensive BASIX Certification Services rather than acting as a building certifier.
Do I need a BASIX consultant?
Almost every new dwelling in NSW requires a BASIX consultant, because the thermal comfort section of the assessment must be prepared by an accredited NatHERS assessor. A consultant is essential when the DIY thermal method does not apply – for example, non-standard geometry, high glazing, or split-level designs – and is strongly recommended for any project where early design input would improve the outcome.
When Do You Need a BASIX Consultant?
- Almost all new dwellings – the thermal comfort section requires a NatHERS simulation prepared by an accredited NatHERS assessor
- Projects where the DIY thermal method does not apply – non-standard geometry, high glazing, or split-level design
- Alteration and addition projects, where the thermal model of the existing building needs to be incorporated
- Developers and volume builders managing multiple concurrent BASIX assessments across a land release or estate
- Architects and designers who want the NatHERS assessment to inform design decisions early, rather than just validating compliance at DA stage
Why Torple
Torple’s assessors are NatHERS-accredited and have experience across all NSW climate zones, from coastal Sydney through to alpine and regional areas.
Contact Torple for a fixed-price BASIX assessment, or call.
We respond to all quote requests within one business day.
BASIX Certificate Requirements - Compliance Through Construction
A BASIX certificate is not the end of the compliance journey – it sets commitments that must be carried through design documentation, construction, and final sign-off. Below is what is required at each stage.
Pre-DA Requirements
- The BASIX certificate must be generated before lodging the DA or CDC
- The certificate must be current – valid for 3 months from its issue date
- The certificate number must appear on all DA drawings
- All BASIX commitments – fixtures, materials, systems – must be shown on the DA plans and specifications
During Construction
- All materials and systems installed must match the commitments listed in the BASIX certificate
- If design changes occur post-consent that affect BASIX commitments, a revised BASIX certificate must be obtained before proceeding
- Critical Stage Inspections (CSIs) may check BASIX compliance items such as insulation and water fittings
At Occupation Certificate Stage
- The private certifier issues a BASIX completion receipt confirming all commitments have been fulfilled
- Without the BASIX completion receipt, an Occupation Certificate cannot be granted
- The OC cannot be issued until the certifier has confirmed BASIX compliance on site
BASIX Certificate Revisions
If the design changes after the certificate is issued but before the DA is determined, a revised certificate must be generated through the BASIX tool. If changes occur after DA approval, the consent authority may require a section 4.55 modification. This is an important consideration for clients undertaking late design changes—our BASIX Compliance Services team ensures that all documentation is revised and approved swiftly before your Development Application proceeds.
Full detail on how BASIX requirements are applied and verified is available from the NSW Planning Portal – How BASIX standards apply.
Torple's BASIX Assessment Service - What to Expect
Torple provides BASIX assessments for residential projects across NSW – from single dwellings and granny flats through to multi-dwelling developments and apartment buildings.
What Torple Needs to Begin
- Architectural drawings – floor plan, elevations, and site plan with orientation
- Window schedule – glazing area, location (orientation), and glass type if specified
- Proposed wall, ceiling, and floor assembly details (or Torple will model to meet the required target)
- Hot water system type – heat pump, solar, electric, or gas
- Project address and lot/DP number, for climate zone auto-population
- Development type – new dwelling, duplex, alteration/addition, or granny flat
What You Receive
- Completed BASIX certificate PDF – ready for DA or CDC lodgement
- NatHERS assessment report covering the thermal comfort section, signed by an accredited assessor
- Stamped NatHERS plans, required for DA submission alongside the certificate
- One revision round included if design changes occur before lodgement
- Advice on design modifications if targets are not initially met
Turnaround
Standard BASIX assessments are completed in 3 to 5 business days. NatHERS-only resubmissions take 2 to 3 business days. An expedited service is available for urgent DA deadlines.
BASIX Frequently Asked Questions
The following questions reflect the most common search queries around BASIX in NSW. Answers are structured for both direct reader use and AI engine extraction, and should be marked up with FAQPage JSON-LD schema on publication.
What is BASIX?
BASIX (Building Sustainability Index) is a NSW Government initiative that is mandatory for new residential buildings and major renovations in NSW. It assesses every proposed home against three sustainability targets: water efficiency, energy use, and thermal comfort. A home cannot receive development approval without meeting all three.
What is a BASIX certificate?
A BASIX certificate is the formal compliance document generated via the NSW Planning Portal’s BASIX tool, confirming a proposed home meets the required water, energy, and thermal comfort targets. It is required for Development Application or Complying Development Certificate lodgement and remains valid for 3 months from the date of issue.
Do I need a BASIX certificate in NSW?
Yes, if your project is a new dwelling (Class 1), a Class 2 apartment building, a swimming pool over 40,000 litres, or an alteration or addition with a cost of works of $50,000 or more. A BASIX certificate is not required for minor renovations that fall below these thresholds.
How much does a BASIX certificate cost?
Cost has two components: the NSW Planning Portal processing fee (a maximum of $50 for a single dwelling, $80 for the first two dwellings of a multi-dwelling project plus $35 per additional dwelling, and a further $30 where a NatHERS certificate is required), plus a NatHERS assessor fee typically ranging from $250 to $600 for a standard house. Total cost varies with project size and complexity.
How long is a BASIX certificate valid?
A BASIX certificate is valid for 3 months from its date of issue. If the DA or CDC is not lodged within this period, a new certificate must be generated.
What is the 7-star BASIX requirement?
Since 1 October 2023, the BASIX thermal comfort target requires a minimum of 7 NatHERS stars per dwelling. This replaces the previous average of 5.5 to 6 stars required under the former BASIX SEPP 2004.
What is the BASIX portal?
The BASIX portal is now fully integrated into the NSW Planning Portal at planningportal.nsw.gov.au. The legacy basix.nsw.gov.au tool was migrated into the Planning Portal in October 2023, and access now requires a NSW Planning Portal account.
Who can issue a BASIX certificate?
BASIX certificates are generated by the applicant – or their consultant – directly through the NSW Planning Portal’s BASIX tool. No council or government officer issues them manually; the tool generates the certificate automatically once all three targets are passed.
What is a BASIX certifier?
A BASIX certifier is a private building certifier who verifies that BASIX commitments have been fulfilled during construction, and who issues the BASIX completion receipt at Occupation Certificate stage. This is a distinct role from a BASIX consultant, who prepares the NatHERS thermal assessment before construction begins.
Is BASIX required in all of NSW?
Yes. BASIX applies across the whole of NSW – metropolitan Sydney as well as every regional, rural, and coastal area. Specific targets vary by climate zone and local government area, but the requirement to obtain a certificate applies everywhere in the state.
What are the requirements for a BASIX certificate?
A BASIX certificate must be generated before lodging the DA or CDC, must be current (valid for 3 months from issue), and its number must appear on all DA drawings. During construction, all installed materials and systems must match the certificate’s commitments. At Occupation Certificate stage, the private certifier must confirm compliance and issue a BASIX completion receipt before the OC can be granted.
Q: Can I apply for a BASIX Certificate myself?
While applicants can use the online tool, partnering with professional BASIX Consultants NSW ensures that complex thermal and energy targets are optimized correctly before lodgement.
Q: How long does a BASIX Assessment take?
Standard assessments handled by BASIX Experts typically take 3 to 5 business days, with expedited options available for urgent deadlines.