The Building Code of Australia – compliance issues

The Building Code of Australia (‘BCA’) contains a series of technical provisions that dictate a range of minimum acceptable standards in respect of the design and construction of buildings and various other structures. It is produced and updated by the Australian Building Codes Board on behalf of the Commonwealth Government and all State and Territory governments.

The BCA is found in the first two chapters of the National Construction Code (‘NCC’) and has been in effect since 1 May 2011.

Why do we need a national building code?

The BCA was introduced as a means of ensuring that minimum construction standards around the country were consistent. Compliance with the BCA’s technical requirements is therefore mandatory in all States and Territories.

What does the BCA cover?

The BCA covers a broad range of building and construction related matters including standards for structural adequacy, fire resistance requirements, energy efficiency and sustainability, issues that affect the health and amenity of building occupants and matters concerning access and egress.

How do I know if my building complies with the BCA?

The technical requirements of the BCA are split into two volumes.

In order to ascertain whether your building is compliant, or the steps you need to take to ensure that it becomes compliant, the first thing you need to do is determine which volume your building comes under.

Technical requirements in the BCA depend on which class of building is involved. There are 10 possible classes of buildings and these are divided between the BCA volumes as follows:

  • Volume One – Commercial Buildings – covers requirements for all Class 2 to 9 buildings (commercial buildings) as well as access requirements for persons with a disability (Class 1b and 10a buildings) and Class 10b swimming pools which all have access requirements for people with a disability; and
  • Volume Two – Housing provisions – includes Class 1 and 10a buildings (save and except for access requirements for persons with a disability in Class 1b and 10a buildings), specified Class 10b structures (again, other than access requirements for persons with a disability in Class 10b swimming pools) and Class 10c private bushfire shelters.

Do the same standards apply to domestic and commercial dwellings?

Not surprisingly, the BCA provisions for housing differ significantly from those that apply to commercial buildings. If you are in any doubt as to what volume your construction will be covered by, especially if you are considering a mixed use development, then it is always prudent to seek legal advice prior to embarking on any construction rather than waiting and finding out at the end of construction that minimum standards have not been met.

Does the BCA prescribe all aspects of a build including mandatory materials?

The aim of the BCA is not to dictate that only certain materials or building methods will be permitted to be used if a building is to be compliant. Rather, the BCA is a performance-based building code. This means that the use of alternative materials, designs and even construction methods may be permitted provided the minimum standard requirements of the code are met.

In this way innovative materials and new construction methods can be allowed with designs being tailored to suit a particular build and flexibility of design is allowed provided the intent of the BCA is met. The aim of the BCA is to set minimum standards not to dictate what materials or designs can be used to achieve those standards.

How is compliance with the BCA assessed?

Just as no single building method or material is prescribed as being mandatory by the BCA there is also no single method of assessment applied to determine compliance. Under the BCA there are several acceptable assessment methods available including:

  • Evidence based assessment – which allows for the provision of a report from Registered Testing Authority, a current Certificate of Accreditation or Certificate of Conformity, a certificate prepare by either a professional engineer or some other appropriately qualified person, a current certificate issued by a product certification body provided that body has been accredited by the Joint Accreditation System of Australia and New Zealand or any other form of acceptable documentary evidence that is able to adequately demonstrate suitability for use;
  • Verification methods – including calculations or mathematical models or tests using a technical operation either on site or under suitable laboratory conditions;
  • Alternative method (sometimes referred to as any other method) – alternative methods may be used provided the relevant authority is satisfied that compliance with the BCA has been achieved. In making such a decision an approval authority may have regard to relevant deemed-to-satisfy provisions or verification methods provided for in the BCA;
  • Expert judgment – in situations where tests or modelling calculations are not available the opinion of a technical expert may be acceptable; and
  • Comparison – a comparison is made between the proposed building method and the ‘deemed-to-satisfy’ method set out in the BCA. Provided that it can be demonstrated to the approval authority that the proposed building solution is either equivalent or superior to the ‘deemed-to-satisfy’ provision, then the proposed method or material may be deemed to meet the relevant performance standard.

Although the BCA is designed as a plain English document navigating your way around the BCA does require a certain degree of prior knowledge and skill. If you have any questions or would like assistance in understanding the BCA or ensuring your building complies with the BCA requirements we would be happy to assist.

If you or someone you know wants more information or needs help or advice, please contact us on +612 9248 3450 or email