Yes. Your BASIX Certificate should match the architectural plans, specifications and approval documents submitted for your NSW residential project. BASIX is not a separate document that sits outside the design. It records sustainability commitments that need to be coordinated with the drawings and then carried through approval, construction and certification.
NSW Planning explains that the BASIX Certificate lists key elements of the design, known as sustainability commitments, and that the certificate must be submitted with the development application or complying development certificate. For the construction certificate stage, the BASIX Certificate must be attached and the BASIX commitments must be shown on the plans. The project must then be built according to those commitments. NSW Planning Portal
A BASIX Certificate needs to match the plans because the certificate commitments become part of the project documentation. Items such as glazing, insulation, hot water, rainwater, solar panels, heating, cooling, ventilation, pools and spas should be consistent with the drawings and specifications submitted for approval.
A BASIX Certificate is based on information from the project design. If that information does not match the plans, the approval documents may become inconsistent. This can create problems because the certificate is not just a general sustainability statement. It includes specific commitments that may need to be shown on drawings, included in specifications or delivered during construction.
For example, if the BASIX Certificate assumes a particular glazing performance, insulation level, rainwater tank, hot water system or solar panel commitment, those items should be understood by the designer, builder, certifier and client. If the plans show something different, the project team may need to update the plans, update the certificate or confirm the correct commitment before moving forward.
BASIX commitments are the sustainability measures listed on the BASIX Certificate. These are the project features and specifications used to show that the development meets the required water, energy and thermal performance standards. NSW Planning describes these as key elements of the design recorded on the certificate.
Common BASIX commitments may include:
The main items that need to match are the items used in the assessment and listed as commitments. This can include details shown on the architectural plans, window schedule, specification notes, hydraulic information, mechanical information, solar layouts or pool drawings. The more specific the BASIX commitment is, the more important it is that the design documents are consistent.
Important items to check include:
If the BASIX Certificate does not match the plans, the project may need clarification before it can proceed. The issue may be picked up by the designer, builder, certifier, council or assessor. Depending on the difference, the solution may be as simple as updating a note on the plans or as involved as revising the BASIX Certificate and related thermal comfort assessment.
Inconsistencies can cause delays because approval and certification documents need to tell the same story. If the BASIX Certificate says one thing and the plans show another, the project team may need to confirm which document is correct before lodgement, construction certification or occupation certification can continue.
Yes. BASIX inconsistencies can delay approval if they are discovered before lodgement, during assessment or at the construction certificate stage. The NSW Planning Portal states that for a construction certificate, the BASIX Certificate must be attached and all BASIX commitments must be shown on the plans. This means the project team should not wait until construction to check whether the plans and certificate align.
The same issue can continue later in the project. NSW Planning explains that the certifying authority will only issue a final occupation certificate when satisfied that the project has been built as described on the BASIX Certificate. This makes consistency important from early design through to completion. NSW Planning Portal
Yes. At the construction certificate stage, BASIX commitments need to be shown on the plans. This may include written notes, specification references, drawings, schedules or other documentation that clearly shows how the BASIX commitments will be delivered. The exact format may depend on the project and the documentation requirements of the certifier or approval authority.
For example, a rainwater tank commitment may need to be shown on the site plan or hydraulic documentation. Window performance may need to align with the window schedule. Insulation levels may need to appear in construction notes. Solar commitments may need to be reflected in the roof plan or energy documentation.
If the plans change after the BASIX Certificate is issued, the certificate should be checked before the updated plans are lodged, certified or built. Some changes may not affect BASIX. Other changes may affect water, energy or thermal comfort commitments and may require the certificate to be revised.
Changes that should usually be checked include:
The best way to avoid mismatches is to treat BASIX as part of the design coordination process rather than a final document added at the end. The plans should be developed enough for assessment, and the assessor should be told about any known design changes before the certificate is issued.
Certified Energy prepares BASIX Certificates for NSW residential projects and can help check whether the certificate assumptions match the plans and specifications. Our team can review glazing, insulation, hot water, rainwater, solar, pool, spa and thermal comfort assumptions before lodgement or when the design changes.
If the project also requires NatHERS thermal comfort modelling, we can coordinate the BASIX and NatHERS components together so the certificate, model and approval documentation are aligned.
Send your plans and BASIX documentation to Certified Energy and our team can review whether the commitments align with the project drawings.
Request a ReviewYes. The BASIX Certificate should match the architectural plans, specifications and approval documents submitted for the project. BASIX commitments must be shown on the plans for the construction certificate stage, and the project needs to be built according to the BASIX commitments.
BASIX details that should match the plans include glazing, insulation, construction systems, floor areas, hot water, rainwater tanks, solar panels, pools, spas, heating, cooling, ventilation and any other water, energy or thermal comfort commitments listed on the certificate.
If the BASIX Certificate does not match the plans, the project may need clarification, amended drawings, an amended BASIX Certificate or further review by the certifier, council or approval authority. Inconsistencies can delay approval, construction certification or occupation certification.
Yes. NSW Planning explains that if the application is approved, the project must be built according to the BASIX commitments. A final occupation certificate is only issued when the certifying authority is satisfied that the project has been built as described on the BASIX Certificate.