Performance Solutions

A performance-based solution should result in a better design outcome for the client and is usually adopted when there are difficulties in applying a DtS design. This can particularly apply to existing buildings.

A Performance Solution is required to be prepared by a suitably qualified person. This person will vary depending on the issue being considered. The most frequently adopted Performance Solutions relate to:

• Fire protection (usually at the design stage) where there are a diversity of solutions and issues to consider. These would normally be prepared by a fire engineer. Refer Acumen note Performance Solutions in fire engineering.
• Minor non-conformances relating to access for people with disabilities (this can occur at design or construction stage). These would be normally prepared by an accredited access consultant.
• Utilisation of J1V3 method to determine compliance with Section J of the NCC Volume One.
• F3P1 Weather Proofing of External Walls that has no DtS details and will require a Performance Solution.

Performance-based solutions can, but not necessarily, entail additional cost in the design outcome and also fees to develop the design. This needs to be assessed on a case-by-case situation. It will mean an additional fee to the author of the Performance Solution in preparation and presentation of the Performance Solution to the certifier/building surveyor for acceptance. However, the cost savings achieved through the implementation of the performance solution during construction in most cases for the as-built design outweigh the cost of the Performance Solution development.

The potential for performance-based solutions being included as part of the design and their implications should be included in fee agreements, or if not included should be clearly highlighted as an exclusion within the agreement.

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Process

The process that the person preparing the Performance Solution needs to follow is set out in the NCC and outlined below. This will require input from the architect and consultants depending on the Performance Solution and can be an evolutionary process as the design is refined.

The process for a Performance Solution is:

• Prepare a performance-based design brief and acceptance criteria - This may require collaboration with key stakeholders to determine and agree the relevant criteria to be met and how to determine compliance with the relevant criteria. The certifier/ building surveyor should provide advice on which stakeholders must be included.
• Carry out analysis, modelling or testing - This should include details of the proposal and supporting evidence and an agreed method of testing/ evaluation using one of the methods outlined in the NCC.
• Collate and evaluate results - This includes an assessment of the proposal against the acceptance criteria. It may require another consultation with key stakeholders and acceptance by them.
• Prepare a final report - This will then be assessed and needs acceptance by the certifier/ building surveyor. It is the certifier/ building surveyor who will determine compliance and whether the information presented in the final report adequately demonstrates compliance.

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Issues to consider

Performance-based design brief (PBDB)

The performance-based design brief (PDBD) is prepared by the author of the Performance Solution in collaboration with the architect and design consultants. It will also involve stakeholders such as client/ owner, developer and occupier.

A performance-based design brief (PBDB) is a document that is developed in collaboration with key stakeholders as part of a proposed performance-based design and approval process. When completed, the PBDB becomes the platform upon which the proposed design is constructed.

The purpose of the PBDB is to record fundamental activities and outcomes of the performance-based design process, as agreed during key stakeholder negotiations. When the PBDB is finalised all critical activities and outcomes would have been identified. Consequently, the design process can be commenced with a high degree of confidence that provided the requirements of the PBDB are achieved, the proposed design is likely to be approved.

A need for ongoing discussion is usually determined by the success of initial negotiations and/or the complexity of the proposed solution(s) (ABCB 2022a).

The PBDB would normally contain:

• an understanding and overall context of the project
• identification of relevant stakeholders
• the verification method selected to determine compliance and why this is the appropriate mechanism
• a detailed description of the proposed design
• a detailed description of the performance requirements to be met by the design
• how the assessment will be undertaken and what are the acceptance criteria to confirm compliance.

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Assessment

The assessment is undertaken by the author of the Performance Solution who will need supporting evidence from the architect and design consultants.

Any research and details applicable to the situation, including modelling and testing, can be used to test and assess the proposal against the relevant performance requirements.

The method can be one or a combination of the following assessment methods:

• Evidence of suitability in accordance with Part A5 that shows the use of a material, product, plumbing and drainage product, form of construction or design meets the relevant Performance Requirements.
• A Verification Method including the following:
  • The Verification Methods provided in the NCC.
  • Other Verification Methods, accepted by the appropriate authority that show compliance with the relevant Performance requirements.
• Expert Judgement
• Comparison with the Deemed-to-Satisfy Provisions (ABCB 2022b)

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Use

Performance Solutions can be opportunities to improve design outcomes and not a means to overcome a problem. Their use should be driven by the performance criteria.

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Architect’s role

An architect’s role in a Performance Solution can be:

• The initiator of a design that is not DtS, who then seeks expert advice as to whether it will meet performance requirements. In this way an architect can ‘project-manage’ the development of the Performance Solution seeking input and expertise from others.
• To act as a stakeholder providing information related to the proposed design to the author of the Performance Solution.

When an architect takes on the role of ‘project-managing’ the Performance Solution, the architect will develop the documentation required and follow the process outlined within the NCC. However, the architect generally should not be providing advice unless they are recognised as able to provide ‘expert judgement’ as defined by the NCC. By default, architects are not considered able to provide expert judgement in building and material sciences, unless they hold specialised and specific experience and expertise.

The NCC 2022 defines Expert judgement as:

‘The judgement of an expert who has the qualifications and experience to determine whether a Performance Solution or Deemed-to-Satisfy Solution complies with the Performance Requirements. Contemporary and relevant qualifications and/or experience are necessary to determine whether a Performance Solution complies with the Performance Requirements. The level of qualification and/or experience may differ depending on the complexity of the proposal and the requirements of the regulatory authority. Practitioners should seek advice from the authority having jurisdiction or appropriate authority for clarification as to what will be accepted.’ (ABCB 2022c)

In areas where there is no appropriate authority, the building surveyor will determine if they deem someone as an expert. However, a building surveyor cannot deem an architect as being able to provide expert judgement unless the architect accepts that responsibility. Architects must always ensure they are not providing advice beyond that which is included within their professional Indemnity insurance.

Even if a design can use a CodeMark certificate or a report from an accredited testing laboratory to demonstrate its suitability, the Performance Solution process and reporting still needs to be completed. While the certificate fulfills the ‘evidence of suitability’ requirement, stakeholders must assess its suitability, and the necessary reporting must be completed to meet the full requirements of the Performance Solution process.

Architects should seek information from the certifier/ building surveyor if more detailed information is required as the certifier/ building surveyor have the authority to determine whether the prepared documentation meets the requirements of the NCC.

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Further reading

• Australian Building Code Board (ABCB) - The ABCB provides a number of resources for the production of performance solutions. The primary resource is the Performance Solution Process Handbook.
• ABCB resources - A comprehensive list of resources can be found here.
• National Construction Code 2022 Volume One/Volume Two – Building Code of Australia Part A2 Compliance with the NCC Clause A2G1 – A2G4 NCC Online.

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References

• ABCB (2022a) Performance Solution Process Guidance Document.
• ABCB (2022b) National Construction Code 2022 Volume One/Volume Two - Building Code of Australia Part A2 Compliance with the NCC, NCC Online.
• ABCB (2022c) National Construction Code 2022 Volume One/Volume Two -Building Code of Australia Glossary, NCC Online.

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