The BASIX Portal: How to Use It for Applications in NSW

---

For complex projects or designs struggling to meet targets, professional input is often required to avoid unnecessary delays or redesigns.The BASIX portal is the online assessment system used in New South Wales (NSW) to generate BASIX certificates for residential development projects. It is accessed through the NSW Planning Portal and is where sustainability details for a proposed build are entered, assessed, and certified.

While the NSW Planning Portal manages application lodgement, the BASIX portal is specifically used to assess whether a residential design meets mandatory water efficiency, energy use, and thermal comfort requirements. Understanding how the BASIX portal works is essential, as errors or misunderstandings can delay approvals or create compliance issues later in a project.

This guide explains what the BASIX portal is, how it fits into the NSW planning process, what information it requires, and the most common issues applicants encounter.

What Is the BASIX Portal?

The BASIX portal is the online BASIX assessment tool used to complete sustainability assessments required for most residential developments in NSW.

Through the BASIX portal, applicants enter project details that are assessed against NSW Government sustainability targets. Once those targets are met, a BASIX certificate can be generated and submitted with a Development Application (DA) or Complying Development Certificate (CDC).

Importantly, the BASIX portal does not replace the NSW Planning Portal. Instead, it functions as a linked assessment system within the overall planning framework.

BASIX Portal vs NSW Planning Portal

These two systems are often confused, but they serve different roles:

NSW Planning Portal

• Used to create an applicant account
• Used to lodge DAs, CDCs, and related planning documents
• Manages communication with councils and certifiers

BASIX Portal

• Used to complete the sustainability assessment
• Evaluates water, energy, and thermal performance
• Generates the BASIX certificate once requirements are met

In short, the Planning Portal manages approvals, while the BASIX portal assesses sustainability compliance.

When Is the BASIX Portal Used?

The BASIX portal is used for most residential development scenarios in NSW, including:

• New dwellings
• Dual occupancies and multi‑dwelling developments
• Renovations or additions valued at $50,000 or more
• Swimming pools or spas over 40,000 litres

The BASIX assessment must be completed before a DA or CDC can be formally lodged. Without a BASIX certificate generated through the BASIX portal, councils and certifiers cannot approve the application.

What Information Is Required in the BASIX Portal?

To complete a BASIX assessment through the portal, detailed project information is required. This typically includes:

• Site details and location
• Building type and floor areas
• Window sizes, glazing types, and orientation
• Insulation levels and construction materials
• Water fixtures, appliances, and rainwater systems
• Heating, cooling, lighting, and hot water systems

Accurate and consistent information is critical. Data entered into the BASIX portal must align with architectural plans submitted through the Planning Portal.

How BASIX Applications Work Inside the Portal

Once project information is entered into the BASIX portal, the system evaluates the design against prescribed sustainability targets.

If the design meets the requirements:

• A BASIX certificate can be generated
• The certificate lists specific sustainability commitments
• These commitments become a binding part of the approval

If targets are not met, the design must be adjusted and reassessed before a certificate can be issued.

Common BASIX Portal Issues (And How to Avoid Them)

Inconsistent Plans and Portal Inputs

One of the most common issues is a mismatch between architectural drawings and information entered in the BASIX portal.

How to avoid it:

Ensure the BASIX assessment is based on final, coordinated plans.

Design Changes After BASIX Submission

Changing glazing, insulation, fixtures, or systems after completing the BASIX assessment can invalidate the certificate.

How to avoid it:

Review BASIX impacts before making design changes.

Thermal Performance Failures

Thermal comfort is often the hardest target to achieve, particularly for designs with large glazing areas or poor orientation.

How to avoid it:

Address thermal performance early in the design phase.

Treating BASIX as a One‑Off Task

BASIX commitments apply throughout construction, not just at approval.

How to avoid it:

Ensure builders and certifiers understand the approved BASIX commitments.

What Happens After the BASIX Portal Submission?

Once a BASIX certificate is generated through the BASIX portal and lodged:

• It must be attached to the DA or CDC
• BASIX commitments must be shown on approved plans
• Certifiers will check compliance during construction
• Non‑compliance can delay occupation certificates

In many cases, a BASIX compliance or completion check is required before final approval.

Who Typically Uses the BASIX Portal?

The BASIX portal is commonly used by:

• Designers and architects
• Builders and developers
• Homeowners completing smaller projects
• BASIX consultants and NatHERS assessors

Final Thoughts

The BASIX portal plays a critical role in NSW residential approvals, but it is often misunderstood. While it sits alongside the NSW Planning Portal, its function is very specific: assessing and certifying sustainability performance.

By understanding how the BASIX portal works, what information it requires, and where problems commonly occur, applicants can avoid approval delays and construction‑stage compliance issues.

Treating BASIX as an integrated part of the planning process—not just a technical requirement—leads to smoother approvals and more predictable project outcomes.

Is the BASIX Portal stressing you out?

We help you get fast, accurate, council‑ready BASIX certificates — without the stress, confusion, or costly redesigns.

• Fast Turnaround
• Clear Guidance 
• Cost‑Effective & Collaborative Solutions 

Ready to organise your BASIX certificate? Check out our BASIX page to get starting prices & organise your complimentary quote.