A BASIX consultant reviews a proposed residential development, identifies the appropriate assessment pathway and prepares the information needed to generate a BASIX Certificate for a New South Wales planning or approval application.
The role can include reviewing architectural plans, entering water and energy information, coordinating the thermal-performance assessment, testing practical design changes and checking that the resulting BASIX commitments are consistent with the project documentation.
A BASIX consultant does not approve the development or replace the architect, engineer, builder or certifying authority. The consultant’s role is to prepare and coordinate the sustainability assessment information required for the proposed residential project.
In Brief
A BASIX consultant translates the proposed residential design into the inputs required by the NSW BASIX assessment tool. The consultant reviews the plans, completes the applicable water and energy sections, determines how thermal performance will be assessed and coordinates any required NatHERS simulation. They may also identify practical design changes where the project is not meeting its requirements, prepare the BASIX Certificate and help keep its commitments aligned with the approval drawings.
A BASIX consultant is an industry professional who prepares, coordinates or advises on BASIX assessments for residential development in NSW.
The title describes the consultant’s practical role within the project. It should not be confused with the formal role of an accredited NatHERS assessor, who is authorised through a recognised Assessor Accrediting Organisation to conduct thermal simulations for the BASIX Thermal Comfort Index.
A BASIX consultant may also be an accredited NatHERS assessor. Where that is the case, the same consultant may be able to prepare both the thermal simulation and the wider BASIX assessment. Where the consultant is not accredited for NatHERS simulation, that component must be completed by an appropriately accredited assessor.
The exact service therefore depends on the consultant’s qualifications, the type of project and the thermal-performance method being used.
Important Distinction
A BASIX consultant may coordinate the complete assessment, including project details, water, energy and certificate preparation. An accredited assessor has a specific formal role: conducting an approved thermal simulation and issuing the associated NatHERS Assessor Certificate.
Before appointing a consultant, confirm whether thermal simulation is included, whether it will be completed in-house and whether the person conducting that simulation holds current assessor accreditation.
01
Identify the residential project type, review the available plans and determine which BASIX application pathway and assessment information are relevant.
02
Read the site plan, floor plans, elevations, sections, glazing schedule and construction details needed to describe the proposed development accurately.
03
Record relevant fixtures, rainwater systems, landscape areas, hot-water systems, heating, cooling, ventilation, lighting and other applicable project selections.
04
Determine whether an available simplified method is appropriate or whether the design requires thermal simulation by an accredited NatHERS assessor.
05
Review practical changes to glazing, shading, insulation, systems or other inputs where the proposed design is not meeting the applicable BASIX requirements.
06
Complete the required assessment fields, review the commitments and generate the BASIX Certificate once the applicable requirements have been satisfied.
The consultant’s work begins with the proposed development rather than with the BASIX tool itself. Before entering information, the consultant needs to understand what is being designed and what documentation is available.
The initial review may consider:
This step helps prevent the assessment from being created under the wrong project type or based on incomplete assumptions.
A BASIX assessment is built from information contained in the project documentation. The consultant must interpret that information accurately and identify anything that is missing, inconsistent or not yet resolved.
Depending on the development, the review may include:
Where the drawings and schedules provide different information, the consultant may need clarification before the assessment can be finalised. Guessing unresolved specifications can produce certificate commitments that the project team did not intend to adopt.
The consultant records the water-related information required for the project. This does not involve designing the complete hydraulic system, but it does require the assessment inputs to match the proposed plans and specifications.
Relevant information may include:
The resulting commitments may affect the architectural, landscape and hydraulic documentation. The consultant therefore checks that nominated measures can be carried through into the approval set.
The energy section records the proposed systems and services that influence operational energy use and associated emissions within the BASIX assessment.
The consultant may review and enter information relating to:
The consultant may identify more than one way to achieve the required outcome, but the final selections should reflect systems the client and design team are prepared to document and install.
Thermal performance is one of the most technically detailed parts of the BASIX process. The consultant first needs to establish which assessment method is available and appropriate for the proposed design.
Some eligible single-dwelling designs may use the BASIX Thermal Comfort DIY Method. Other projects require or benefit from the Simulation Method, which uses approved NatHERS software and must be completed by an accredited assessor.
For a simulated assessment, the work may include:
Where the BASIX consultant is also the accredited assessor, these tasks may be delivered as one coordinated service. Otherwise, the BASIX consultant and NatHERS assessor need to exchange consistent plans, specifications and results.
Who can perform a NatHERS assessment? →
Where the project does not meet an applicable BASIX requirement, the consultant can help identify which part of the assessment is driving the result.
The appropriate response depends on whether the issue relates to water, energy, heating performance, cooling performance or the coordination of multiple inputs. A generic upgrade is not always the most effective solution.
Possible adjustments may include reviewing:
The consultant should explain the consequence of each proposed change so the architect, designer, builder or homeowner can make an informed decision. The objective is not simply to add the highest available specification, but to find an appropriate response for the actual design.
Explore design optimisation and BASIX →
A BASIX Certificate contains commitments that must be reflected in the project documentation. Preparing the assessment is therefore not only a data-entry exercise. The consultant must also check that the certificate and drawings describe the same proposed development.
Coordination commonly includes checking:
Where the plans change after the assessment, the consultant should determine whether the BASIX Certificate or supporting thermal assessment also needs to be revised.
Once the applicable assessment requirements have been met and the project inputs have been reviewed, the consultant can generate the BASIX Certificate through the NSW Planning Portal.
The final consultant package may include:
The BASIX Certificate is then submitted with the relevant development or complying development documentation. The applicant and project team remain responsible for ensuring the final approval set incorporates the required commitments.
Residential designs often continue to develop after the first BASIX Certificate is issued. Windows may change, construction systems may be substituted or different services may be selected during documentation or procurement.
The consultant can review changes involving:
Some changes may have little effect, while others can alter the project’s water, energy or thermal-performance result. The assessment should be checked before revised plans are lodged or substituted products are installed.
Plans
Fabric
Systems
The BASIX consultant supports one defined part of the wider design and approval process. Unless separately engaged and appropriately qualified, the consultant does not replace other project professionals.
A standard BASIX service does not generally include:
Where an issue falls outside the BASIX assessment, the consultant may identify the coordination requirement and refer it back to the architect, engineer, planner, builder or certifying authority.
No. NatHERS simulation must be completed by an appropriately accredited assessor. Confirm whether the appointed BASIX consultant also holds that accreditation or coordinates the simulation through another assessor.
No. The consultant prepares assessment documentation. The relevant consent authority or certifying authority determines the planning or approval application.
A preliminary assessment can begin before every selection is final, but the issued commitments must ultimately align with the proposed development. Unresolved information may need to be confirmed before the Certificate is generated.
A well-coordinated assessment should identify why the project is not meeting a requirement and consider suitable responses. Higher-cost glazing or equipment is not automatically the only or best solution.
Relevant changes to the design, glazing, construction or systems may require the BASIX assessment and supporting thermal documentation to be revised.
Frequently Asked Questions
A BASIX consultant typically reviews the residential plans, completes the applicable assessment inputs, coordinates thermal performance, identifies any required design changes and generates the BASIX Certificate. The exact deliverables depend on the project and agreed service scope.
Not necessarily. A NatHERS assessor must hold current accreditation to conduct thermal simulations. Some BASIX consultants are also accredited assessors, while others coordinate that part of the work with a separate accredited professional.
Not usually as part of a standard BASIX service. The consultant prepares the BASIX documentation for inclusion with the application. The applicant, architect, planner or another appointed party generally coordinates the wider DA or CDC submission.
The consultant can recommend performance-related changes and test alternatives, but design decisions remain with the client and appointed design team. Proposed changes should be incorporated into the drawings before the assessment is finalised.
The assessment should begin while the plans are sufficiently developed to provide reliable geometry and construction information, but before all documentation is locked. This leaves time to resolve performance issues without disrupting a completed approval set.
The consultant should identify which part of the assessment is not meeting the applicable requirement and review suitable changes. The response may involve water measures, systems, glazing, shading, insulation or another project-specific input.
Yes, subject to access to the project and sufficient documentation. The consultant can review the proposed changes, update the relevant assessment information and generate revised documentation where required.
Related Knowledge
BASIX Certificates and NSW Submission Services →
Who Can Perform a NatHERS Assessment? →
BASIX Project Review
Certified Energy can review the proposed development, confirm the likely assessment pathway and prepare the BASIX and thermal-performance documentation required for the project.
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