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Many of the Deemed-to-Satisfy (DtS) Provisions in the National Construction Code (NCC) are driven by the fire safety objectives of the code. When compliance with the DtS Provisions is not feasible, not cost effective or competes with the design intent, a Performance Solution can provide an alternative methodology to achieve compliance with the NCC.
Performance Solutions can be used to address any deviations from the NCC DtS Provisions, including the structure, amenity, waterproofing and fire safety. This note focuses specifically on Performance Solutions associated with fire safety matters and how they can be used to facilitate flexibility in design, cost efficiencies and environmental sustainability.
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Obtaining a fire engineering Performance Solution
If you are embarking on a new project, refer to Acumen notes When to engage a fire safety engineer and The role of the fire safety engineer in the design team. Once a fire engineering firm is engaged, they will step through the process of preparing a Fire Engineering Brief (FEB), liaising with the stakeholders, undertaking calculations and analysis and finally preparing a Fire Engineering Report (FER) (ie the report that documents the Performance Solution). Be clear about what you want the fire engineer to do – is your intention that the fire engineer develops an all-encompassing fire safety strategy for your building, or do you only need the fire engineer to justify one or two small deviations from the NCC DtS Provisions? It is common for the certifier/building surveyor to produce a list of issues that need to be addressed by the fire engineer, and fire engineers will commonly ask for this list before they start their work. However, a proactive fire engineer should be able to commence their evaluation without waiting for direction from the certifier/building surveyor.
Once onboard, the fire engineer will step through their process methodically and involve you and the other stakeholders as much as needed. Expect to provide them with information and answer some RFIs. Their job is to understand the objectives of all stakeholders in terms of design intent, aesthetics, cost, buildability, sustainability etc, and find a solution that closely meets those objectives while still being ‘fire safe’. The fire engineer may propose different design alternatives and request input from stakeholders as to which options are better and why. The fire engineer will guide the decision making and advocate for the safety of the end users of the building. By following this process, the fire engineer can facilitate flexibility in design, cost efficiencies and optimise environmental sustainability.
Performance Based Design Brief
Since the adoption of NCC 2019 Amendment 1, all Performance Solutions require that a Performance Based Design Brief (PBDB) be undertaken. The PBDB process is intended to set out the proposed Performance Solutions and assessment methods such that all interested parties can agree on the approach, prior to the assessment taking place. When undertaken by fire engineers this process has traditionally been referred to as a Fire Engineering Brief (FEB).
What is the difference between a PBDB and a FEB? A FEB is a special type of PBDB. A FEB covers the aspects required to be covered in a PBDB (refer to further reading), with a fire safety focus given to each of those aspects as well as detailing specific inputs to be agreed upon by stakeholders (such as occupant characteristics, design occupant loads and details of proposed fire scenarios to be assessed). The terms FEB, FEBQ* and PBDB are commonly used interchangeably in the context of fire engineering.
*Note: FEBQ is an acronym for Fire Engineering Brief Questionnaire and is a bespoke form that is required by Fire & Rescue NSW. It includes much of the information that would normally be included in a FEB and so some fire engineering firms provide only the FEBQ to serve as the PBDB.
Note that the FEB is a briefing document (as noted in the title) – it is not a document that can be relied upon for construction. The FEB sets the foundation and the ground rules that govern the preparation of the Fire Engineering Report (FER). When the foundation set by the FEB is robust then the fire engineer is well placed to prepare a high quality FER (which can be relied upon for construction).
Assessment methods
Once the brief has been agreed by the relevant stakeholders, the analysis/ assessment is undertaken by the fire engineer. This process of analysis/ assessment forms the second part of the Performance Solution Process.
FEBs and FERs contain technical information relating to assessment methods and how NCC compliance is proposed to be demonstrated. While primarily for the benefit of the building surveyor, it is worthwhile that architects understand the assessment methods used by a fire engineer on a given project.
The NCC details a number of assessment methods that can be used to demonstrate that a Performance Solution is satisfactory. The FEB will outline which of these (or which combination of these) will be used:
- Evidence of suitability (that shows the use of a material, product or form of construction meets the relevant Performance Requirements) eg a Codemark Certificate.
- Verification methods provided within the NCC eg Verification Method for calculating risk of radiant heat spread.
- Other Verification methods – any verification method that is agreed as appropriate by the project stakeholders.
- Expert judgement – a judgement from a person who is agreed by the project stakeholders as being an expert.
- Comparison to the DtS Provisions – a comparison that shows a design provides a level of safety that is at least equivalent to a DtS compliant building.
Assessments can be qualitative or quantitative. Fire engineering assessment will often rely on engineering calculations, and sometimes rely on fire test data. Assessments can be deterministic (analysis will always give same result) or probabilistic (analysis determines the probability of a given result (or collection of results) occurring).
Evaluation of results
Evaluating the results of an assessment forms the third part of the Performance Solution process. This is undertaken in house by the fire engineer and architects are generally not required to have any oversight or understanding of how this takes place.
The Fire Engineering Report
The Fire Engineering Report (FER) is a culmination of all of the work that the fire engineer has done on the project. The FER documents key aspects of the (fire safety related) design decisions that have been made by the project team, along with the calculations and analysis that justify that the agreed approach achieves an appropriate level of safety.
Some indicators of a quality FER are that:
- It is easy to understand. You don’t necessarily need to comprehend all of the technical data and calculations, but everything in between should be understandable and coherent.
- It is internally consistent.*
- It accurately describes the proposed building.
- It includes a separate and clear list of requirements that must be implemented as part of the building’s design, construction and ongoing management.
- It lists all relevant information that was relied upon to produce it, as well as having a robust list of reference material that has been cited within.
The advantage of having a quality FER is that the document should easily satisfy the regulatory reviews that take place as part of the application for a construction certificate/building permit.
*Note: As a counter example a poor FER that is not internally consistent may state in the executive summary that the building is required to be sprinkler protected, but then in the middle and conclusion of the FER it states that the building is not required to be sprinkler protected.
Review and finalisation of the FER
Architects are recommended to review the FER thoroughly. Pay particular attention to the assumptions and limitations of the FER and provide feedback to the fire engineer if you believe any particular assumption or limitation is not reasonable. Check that the information that the FER was based on is the most recent / most appropriate. Direct any comments or clarifications to the fire engineer.
One of the main goals of your review is to find the list of requirements that must be implemented as part of the building’s design, construction and ongoing management. In most cases this will be a single list in a single location of the FER, however sometimes it is a collection of lists located in different sections of the FER. Add these listed requirements to the architectural drawings where possible (simply making notes on the drawings can achieve this). Or if any of these requirements are not desirable or not possible to implement – discuss with the fire engineer why this is the case so they can propose an alternative approach.
The FER may undergo a small number of revisions as feedback from stakeholders is received and documented. Then the FER is finalised and submitted to the certifier / building surveyor when the project team is applying for the construction certificate / building permit. The final approved FER forms the fourth and final stage of the performance solution process.
Design change and the FER
Despite the best of intentions, it is common for some aspects of a project to change between the time that the FER is completed and the time that construction documentation is completed. While the majority of architectural changes are unlikely to impact on the conclusions of an FER, the only party on the project team that is appropriately qualified to make that determination is the fire engineer. Therefore, it is in your interest and the project’s best interest, to keep the fire engineer informed of any design changes that take place throughout the project. This is best achieved by way of a ‘walk-through’ of the plans with your fire engineer to explain what design aspects have changed since the last revision of the FER. It’s good practice to involve the certifier/ building surveyor in this ‘walk-through’ so that they can identify any potential compliance issues with the NCC DtS Provisions. If there are any compliance issues, an amendment to the FER might be required. Undertaking this process before any construction permit applications or leading up to any major project milestones should eliminate any surprises when the fire engineer attempts to sign off on the design.
Further Reading
- ABCB (2021) Australian Fire Engineering Guidelines (AFEG) – Chapters 1 and 2
- ABCB (2021) Performance Solution process handbook
- ABCB (2022) Performance Solution process guidance document
- Acumen note (2022) The role of the fire safety engineer in the design team
- Acumen note (2022) When to engage a fire safety engineer
About the Author
Mathew Freeman, MFireSafetyEng, BEMech (Hons), NER, CPEng, Technical Development Lead, Holmes Australia, kindly prepared the content of this note.
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