Gaining Fire Regulation compliance through the Alternative Solution path
Some recent innovative timber buildings have been completed, even though they have not met the National Construction Code (NCC) Deemed-to-Satisfy (DtS) Provisions prescriptive fire requirements.
Deemed-to-Satisfy Provisions of the National Construction Code (NCC) do not allow some building elements to be constructed from combustible materials, such as timber, or they nominate the material that can be used, such as concrete or masonry.
Alternative Solutions may be developed by an accredited/registered Fire Safety Engineer as part of a building solution to allow the use of timber in specific applications not covered by the DtS Provisions of the NCC.
On this page you'll find a summary of the process that can be used to develop Alternative Solutions. Three WoodSolutions Technical Design Guides have been written to summarise the Alternative Solution process for each element. The guides are:
- #17 Alternative Solution Fire Compliance: Timber Structures (plus separate CAD files)
- #18 Alternative Solution Fire Compliance: Facades
- #19 Alternative Solution Fire Compliance: Linings
The above titles are available for download at the base of this page. Please note you must be a registered user and logged in. Registration is fast and free - see the top right hand corner of the page.
The Guides are complemented by case studies on this site that show the documentation and evidence required, these include:
- Williamstown High School
- Knox Grammar School Great Hall and Aquatic Centre
- Monash University Student Housing
- Wollongong University AIIM Processing and Devices Building
This site also includes other useful information that could help in developing an Alternative Solution.
National Construction Code Compliance - DtS or Alternative Solution
To demonstrate that a building solution complies, it is necessary to show that it meets the relevant performance requirements of the NCC. The performance requirements can be met by either complying with the Deemed-to-Satisfy construction that is acknowledged as fulfilling the NCC's Performance Requirements (prescriptive) requirements or demonstrating that an Alternative Solution satisfies the Performance Requirements, using an appropriate Assessment Method.
An Alternative Solution is defined in the NCC as follows:
"Alternative Solution means a building solution which complies with the Performance Requirements other than by reason of satisfying the Deemed-to-Satisfy Provisions."
Demonstration of Compliance of a Deemed-to-Satisfy Provision
Deemed-to-Satisfy Provisions are specified in the relevant sections of the NCC. In many instances a Deemed-to-Satisfy Provision may reference another document, rule, specification, standard or similar documents.
Demonstration of Compliance of an Alternative Solution
An Alternative Solution that differs from the Deemed-to-Satisfy Provisions must prove to satisfy NCC Performance Requirements. Suitable assessment methods are identified in the NCC, Volume 1: Section A0.9.
It is important to note that a mixture of Deemed-to-Satisfy Provisions and Alternative Solutions can be used to develop a solution for a building that will meet the Performance Requirements of the NCC. Alternative Solutions can be developed to allow the use of timber-framed construction systems in situations not covered under the Deemed-to-Satisfy Provisions of the NCC.
The process of developing an Alternative Solution
The Alternative Solution process generally begins when the design has progressed to the point where a review by the Building Certifier / Surveyor identifies whether the building complies with the Deemed-to-Satisfy Provisions of the NCC.
Where the building design does not comply with the Deemed-to-Satisfy Provisions, Alternative Solutions are required. To provide consistency in the methodology of formulating fire safety engineering solutions, the Australian Building Codes Board published the International Fire Engineering Guidelines (IFEG), which provides a recommended approach for completing fire safety engineering solutions for an Alternative Solution.
Generally a two stage reporting process is adopted, Fire Engineering Brief (FEB) and a Fire Engineering Report (FER). This involves relevant stakeholders, who in addition to the design team, client and building certifier, and may include the fire brigade, local council, insurer and other interested parties.
Fire Engineering Brief
The first stage is the development of a Fire Engineering Brief. The purpose of the Fire Engineering Brief is to communicate to the relevant stakeholders and approval authorities the objectives and basic strategy by which the fire safety engineering analysis will be completed. The Fire Engineering Brief is to outline the proposed Alternative Solutions including information on the acceptance criteria and any input parameters expected to be used in each Solution.
Fire Engineering Brief which amongst other things documents:
- the stakeholder objectives,
- a trial fire safety strategy for the building,
- potential variations from the Deemed-to-Satisfy Provisions for the trial fire safety strategy,
- relevant performance requirements,
- engineering / assessment method to the adopted,
- fire scenarios to be assessed, if appropriate, and
- the acceptance criteria.
The Fire Engineering Brief is distributed for comment and approval by stakeholders, including the Building Certifier/Surveyor and Fire Brigade. Once agreement is received on the Fire Engineering Brief, then the Fire Engineering Report can be developed.
Fire Engineering Report
The second stage is the development of the Fire Engineering Report which details the formulation and analysis of the fire safety design solutions against the fire safety objectives developed in the Fire Engineering Brief process. Registered / accredited Fire Safety Engineers are normally appointed to prepare a Fire Engineering Report in accordance with the method and process described in the International Fire Engineering Guidelines.
The Fire Engineering Report contains all required calculations, analysis of test evidence and fire modelling to support the recommendations for the formulated fire safety design solution for the building. Often Fire Engineering Reports will nominate levels of performance to be achieved by timber products in fire tests, in which case supplementary documentation will need to be submitted to the regulatory authorities.
Typically the Fire Engineering Report will make use of one or more of the following assessment methods permitted by the NCC.
- Verification methods specified by the NCC, e.g. CVI and CV2
- Comparison with the NCC's Deemed-to-Satisfy Provisions
- An analysis of the holistic fire safety strategy performed by a registered Fire Safety Engineer, using methods agreed during the Fire Engineering Brief process and demonstrating compliance with the acceptance criteria also agreed during the Fire Engineering Brief process.
The most common for engineering design are a comparison with the Deemed-to-Satisfy provisions, use of a verification method, or meeting the methods described in Specification A2.2 "Evidence of Suitability".
The Fire Engineering Brief and Fire Engineering Report process are generally undertaken as the design is developed and tender documentation prepared ensuring that the process does not impact on the construction program.
As the NCC is called into legal effect by each State and Territories' legislation, the approvals process varies between the States and Territories. The Building Certifier/Surveyor should be consulted early to determine the approvals process and likely timelines for each project.
Generally, the Building Certifier/Surveyor is responsible for identifying any deviations from the Deemed-to-Satisfy Provisions and the relevant Performance Requirements to be addressed. They are to review and be responsible for the approval of both the Fire Engineering Brief and Fire Engineering Report. If necessary (for example, due to the complexity of the design), they may seek a third party review of the fire safety engineering design as part of the approvals process.
In many cases, the Fire Brigade are also considered as a "referral authority", requiring the design to be discussed with the local Fire Brigade.
Due to the time associated with reviews by approvals authorities and the inherent risk associated with obtaining approval of Alternative Solutions, time for the completion of the approvals process needs to be taken into account in the project timeline. It is recommended that the Building Certifier/Surveyor is consulted as early as possible as to the circumstances under which they would require a third party review of the fire engineering strategy and whether they would approve the Fire Engineering Brief without having received Fire Brigade comments (as is permitted by the legislation).
Also below: Downloadable CAD details of all relevant drawings in TDG17
The details are available for the following CAD software formats: ArchiCAD (.mod), AutoCAD (.dwg), Revit (.rvt) as well as JPEG and PDF formats
NOTE: Each ZIP file includes a Word document that cross references each CAD detail to the relevant figure in TDG17