BASIX Compliance Checklist for NSW Home Builds and Renovations

A BASIX compliance checklist helps coordinate the sustainability decisions, documents and evidence needed for a relevant NSW residential project. It does not replace the project assessment or professional advice.

The most important distinction is this: the BASIX certificate is the legally operative document, while the BASIX report is for information and cannot be lodged as the certificate. The NSW Planning Portal explains the difference between the BASIX certificate and report.

Quick summary

• Confirm whether BASIX applies to your new home, knockdown rebuild, duplex, granny flat, renovation or extension.
• Gather accurate site information, including site area, roof area, storeys and conditioned floor area.
• Coordinate water efficiency, energy efficiency and thermal performance with the drawings and specifications.
• Check that the BASIX certificate describes the same development shown in the application documents.
• Track BASIX commitments during construction and retain evidence for final certification and handover.

What a BASIX compliance checklist should cover

BASIX is the NSW residential sustainability assessment and certification system for relevant residential development and renovation projects. It addresses three connected areas: water efficiency, energy efficiency and thermal performance. The exact pathway, commitments and documentation depend on the project, its design and the applicable development requirements. Check the current BASIX guidance on the NSW Planning Portal before relying on an older checklist.

“BASIX compliance checklist” is a practical search term, not the name of one universal government checklist for every property. Use the stages below to organise decisions, then confirm project-specific requirements with the relevant designer, builder, certifier or NSW authority.

Stage 1: Confirm whether BASIX applies to your project

Do not assume that every building project or renovation follows the same BASIX process. A new custom home, knockdown and rebuild, duplex, secondary dwelling, extension and alteration may each require a different assessment or approval pathway.

Before design decisions become fixed, ask:

• What type of development is proposed?
• Is it a new, replacement or additional dwelling, or an alteration to an existing home?
• Which approval pathway is being considered?
• Will the work change the roof area, conditioned floor area, glazing, services or thermal envelope?
• Who will confirm whether a BASIX assessment and certificate are required?

For a Western or Northwest Sydney project, BASIX should sit within the wider approvals programme rather than being treated as a last-minute form. An approvals coordination checklist can help place BASIX alongside surveys, architectural plans, engineering information, selections and final certification.

Stage 2: Gather accurate site and project information

The assessment is only as reliable as the information entered into it. The NSW Planning Portal identifies site area, roof area, number of storeys and conditioned floor area as important project details that affect the assessment pathway and performance criteria. Review the Planning Portal’s site details guidance before the assessment is prepared.

Prepare a working information pack containing:

• Property address and relevant site identification details.
• A current site survey showing boundaries, levels, existing structures and constraints.
• Proposed site area, building footprint, roof areas and number of storeys.
• Conditioned floor area and spaces that will be heated or cooled.
• Orientation, window locations and major overshadowing or exposure conditions.
• Existing services and proposed water, hot-water, lighting, cooling and heating arrangements.
• Any existing dwelling or structure affected by the proposed work.

Do not estimate these inputs casually. A changed floor area, roof design, window arrangement or service selection can affect the assessment and the commitments recorded in the certificate.

Stage 3: Align the design and supporting documents

BASIX decisions should be reviewed alongside the design, not after the drawings are complete. Floor plans, elevations, roof design, glazing, building envelope, services and specifications need to describe a consistent proposal.

Before assessment or submission, gather and compare:

• Architectural site plans, floor plans and elevations.
• Roof plans, window and door schedules and relevant sections.
• Site survey and required engineering or geotechnical information.
• Water, lighting, hot-water, heating, cooling and ventilation specifications.
• Insulation, glazing and other building-envelope information.
• Selections schedules and product specifications affecting BASIX commitments.
• Plans for any secondary dwelling, duplex or multi-dwelling component.

Review your custom house blueprints alongside the BASIX documentation. This helps identify whether the proposed layout, sections, envelope and services can support the recorded performance outcomes before pricing, approvals or construction.

The three BASIX performance areas to check

Water efficiency

Check the water-related commitments recorded for the project and confirm that plans and specifications identify the relevant fixtures, systems and connections. Depending on the assessment, this may interact with bathroom and kitchen fixtures, landscaping, rainwater management or other water-use decisions. Do not treat a particular product or system as mandatory without checking the current project assessment.

Energy efficiency

Energy commitments can interact with lighting, hot water, heating, cooling, ventilation, appliances and other services. Confirm that selected systems match the assessed design and that installation or commissioning evidence can be retained.

Thermal performance

Thermal performance is connected to orientation, shading, glazing, insulation, the building envelope and the size and position of openings. A change that appears cosmetic, such as altering windows or roof form, can have wider assessment implications.

Stage 4: Check the BASIX assessment and certificate

Once the assessment is prepared, check the certificate before it is used in the approval process. It should identify and describe the proposed development consistently with the application and accompanying documents. It also records commitments about how the development will be carried out. The BASIX legislation guidance explains the role of the certificate and its commitments.

• Confirm the property and project description.
• Check the number of dwellings, buildings and relevant common areas.
• Compare floor areas, storeys, roof information and other inputs with the drawings.
• Read every listed commitment rather than relying only on the overall result.
• Check that plans, specifications and selections show the assessed solutions.
• Save the final certificate and supporting records in the project file.
• Confirm whether a revised assessment is needed if the design changes.

Who should confirm each BASIX decision?

Question	Ask first	Confirm
Does BASIX apply?	Designer, certifier or NSW authority	Project-specific development and approval requirements.
Are site inputs accurate?	Designer and assessment practitioner	Site area, roof area, storeys and conditioned floor area.
Do drawings match?	Designer	Layout, glazing, envelope, services and assessed design features.
Can commitments be delivered?	Builder and trades	Products, installation details, substitutions and sequencing.
Is documentation complete?	Certifier or approval coordinator	Certificates, plans, statements and supporting records.
Have rules or tools changed?	NSW Planning Portal	Current guidance, validation requirements and certificate process.

Responsibility depends on the project arrangement. Do not assume that a builder, designer or certifier has accepted every BASIX responsibility unless it is clearly agreed and documented.

Stage 5: Coordinate BASIX with the approvals submission

Before submission, compare the BASIX certificate with the development application, construction documentation or other documents required by the relevant pathway. Names, dwelling numbers, plans, areas and design commitments should not conflict.

• Include the current BASIX certificate, not merely the free report.
• Use plans that correspond with the certificate’s development description.
• Include specifications and schedules supporting the commitments.
• Coordinate engineering, survey and sustainability documents.
• Record who reviewed the package and when.
• Set a process for questions, corrections and revised documents.

For duplexes and multi-dwelling projects, check how each dwelling, building and common area is represented. Do not transfer assumptions from a single-home assessment to a multi-dwelling project.

Stage 6: Track BASIX commitments during construction

A certificate does not make construction decisions automatically compliant. Before approving a substitution or variation, compare it with the BASIX commitments and ask whether the assessment, plans or approval documents need review.

• Check that glazing, windows, shading and insulation match the documented design.
• Verify lighting, hot-water, heating, cooling and ventilation systems.
• Confirm water-related fixtures and systems are installed as documented.
• Escalate changes to floor area, openings, roof form or services before work proceeds.
• Retain invoices, product data, installation records, inspection notes and photographs where relevant.

Current BASIX certification material indicates that commitments marked for checking must be fulfilled and supported by relevant evidence. The exact evidence depends on the project and certifier, so agree the record-keeping process before construction reaches the relevant stage.

Stage 7: Complete final compliance and handover checks

At close-out, assemble the records needed to demonstrate what was installed or completed. These may include final inspection evidence, product information, warranties, approved variations, certificates, commissioning records and photographs.

• Compare final work with the BASIX certificate and approved plans.
• Document any design or product changes.
• Complete relevant installation and product evidence.
• Assign actions for outstanding defects or incomplete sustainability items.
• Provide the certifier with records required for the relevant process.
• Store the final certificate and project documents with the home records.

Do not treat a generic checklist as a guarantee of an occupation certificate. Final certification depends on the project, approval pathway, completed work and evidence accepted by the relevant certifier.

Common BASIX checklist mistakes to avoid

• Using the report instead of the certificate: The report is informative, but it is not the legally operative document.
• Entering approximate site data: Incorrect area, storey or floor information can affect the assessment.
• Separating BASIX from design: Treating it as paperwork after design completion can create avoidable changes.
• Assuming commitments are optional: Recorded commitments need to be reflected in completed work.
• Approving substitutions informally: A replacement product or system may affect assessment or approval documents.
• Leaving evidence until handover: Records are easier to collect during procurement and installation.
• Copying another project: Another home or older certificate does not establish requirements for your property.

BASIX compliance checklist FAQ

Does BASIX apply to every new home, renovation or extension in NSW?

No. Applicability depends on the development requirements and project details. Confirm the pathway for the specific property and scope before relying on a generic checklist.

What is the difference between a BASIX certificate and a BASIX report?

The certificate is the legally operative document used for the relevant approval process. The report provides assessment information but cannot be lodged as the certificate.

When should BASIX be completed during a home build?

Coordinate it while the design and project information are being developed, before the relevant approval submission. Review it whenever plans, floor areas, glazing, envelope or services change.

What happens if the design changes after the BASIX certificate is issued?

Ask the designer, assessment practitioner or certifier whether the change affects the assessment or requires updated documentation. Do not assume a change is acceptable because it appears minor.

Who confirms whether completed work meets the BASIX commitments?

The relevant certifier and project professionals confirm the evidence required for approval and certification. The builder and trades should provide accurate installation and product information, while the homeowner should retain final project records.

Conclusion: use the checklist to keep BASIX decisions aligned

The most useful BASIX compliance checklist follows the project from applicability and site information through design, certificate review, approvals, construction and handover. Start with accurate inputs, use the certificate rather than the report, and ensure the drawings, specifications, selections and completed work tell the same story.

For homeowners in Western and Northwest Sydney, King Style Homes coordinates custom homes, duplex projects, granny flats, renovations and knockdown rebuilds through design, approvals, construction and handover. Discuss your site and proposed project with the team early so BASIX coordination can be considered within the wider build pathway.