The Building Code of Australia (“BCA”) forms part of the National Construction Code (“NCC”), a document published by the Australian Building Codes Board (“ABCB”) to provide a nationally consistent framework for the construction of buildings and structures throughout Australia.
The NCC currently comprises three volumes;
- Building Code of Australia, Volume One (Class 2 to Class 9 Buildings)
- Building Code of Australia, Volume Two (Class 1 and Class 10 Buildings)
- Plumbing Code of Australia, Volume Three
In Australia, the Commonwealth of Australia Constitution Act 1900 (“the Constitution”) sets out the roles and responsibilities of the federal and state governments. By convention, matters not specifically addressed in the Constitution remain the power of the States and Territories.
Health, safety and amenity of people in buildings is not addressed in the Constitution. As a result, these matters has been assumed by the States and Territories, leading to an array of differing regulatory frameworks throughout Australia.
Almost 50 years ago in 1967, the complexity of Australia’s regulatory system for buildings and construction was identified as a legislative nightmare. As a result an intergovernmental committee was established by agreement between the States to pool their resources and draft a uniform technical code for building regulatory purposes. The result of their cooperation was a document first published in the early 1970’s called the Australian Model Uniform Building Code (AMUBC).
Again in the early 1980’s it was recognised that the building industry required further reform to encourage national consistency and support modern methods of construction and materials. A new committee was formed leading to the first edition of the Building Code of Australia (BCA), developed in 1988 and published in 1990.
In 1991, the Council of Australian Governments (“COAG”) accepted a recommendation to establishment a new body with the objective of once again reforming building codes throughout Australia. In 1994 the Australian Building Codes Board (“ABCB”) was established, leading to a performanced-based building code, published in 1996.
Since 2003 the ABCB has moved to a yearly amendment cycle for the BCA accommodating ongoing developments in construction related to health, safety, amenity, construction materials and methods.
The Goal of the Building Code of Australia
The goal of the BCA is to enable the achievement of nationally consistent, minimum necessary standards of relevant, health, safety (including structural safety and safety from fire within a building and fire spread to and from other buildings on the allotment and the allotment boundaries), amenity and sustainability objectives efficiently. This goal is applied so—
- there is a rigorously tested rationale for the regulation;
- the regulation generates benefits to society greater than the costs (that is, net benefits);
- the competitive effects of the regulation have been considered and the regulation is no more restrictive than necessary in the public interest; and
- there is no regulatory or non-regulatory alternative that would generate higher net benefits.
Anyone may submit a proposal to change or amend the BCA however all changes must be reviewed by the Building Codes Committee and are then subjected to a Regulatory Impact Assessment process.
The BCA contains technical provisions for the design and construction of buildings and other structures, covering such matters as structure, fire resistance, access and egress, services and equipment, and energy efficiency as well as certain aspects of health and amenity1.
The BCA is given legal effect by building legislation in each State and Territory. This legislation consists of an Act of Parliament and subordinate legislation which empowers the regulation of certain aspects of buildings and structures, and contains the administrative provisions necessary to give effect to the legislation.
Any provision of the BCA may be overridden by, or subject to, State or Territory legislation. The BCA must therefore be read in conjunction with that legislation2.
Structure of the Building Code of Australia
As previously discussed, there are two volumes of the BCA, Volume One and Volume Two. This article relates specifically to the requirements of Volume One however the principles covered are typical for both volumes.
Before we proceed any further, it is vital to explain the application of each volume, and to do that, we need to explain the principles of classification of buildings. The classification of a building or part of a building is determined by the purpose for which it is designed, constructed or adapted to be used.
Just as the BCA is given effect by each state or territory building regulatory legislation, that legislation may also affect the way the BCA classification system is applied.
To assist grouping the classifications of buildings and structures according to which volume of the BCA applies, I have colour coded the table with Volume One in blue, and Volume Two in red, the same colours the external cover of each Volume is published by the ABCB.
Application of the technical provisions of the BCA is dependent on the classification of the building or structure. Therefore it is critical to ensure that the classification applied reflects the purpose or use of the building or structure proposed to be constructed. Some buildings or structures do not fit neatly into these descriptions and therefore require careful consideration by the authority having jurisdiction to determine what requirements will be applied.
A scan of the general table of contents of the BCA reveals the general structure of the document as follows;
- Section A - General Provisions
- Section B - Structure
- Section C - Fire Resistance
- Section D - Access and Egress
- Section E - Services and Equipment
- Section F - Health and Amenity
- Section G - Ancillary Provisions
- Section H - Special Use Buildings
- Section I - Maintenance
- Section J - Energy Efficiency
The General Provisions section sets out the application and framework of the BCA, establishing the important principles and assessment methods to satisfy the Performance Requirements for a Building Solution.
The concept of a Deemed-to-Satisfy solution underpins compliance with the mandatory Performance Requirements as it provides a solution which designers can adopt which is “deemed to comply”. It gives confidence to designer and Authority with Jurisdiction alike that the solution will meet the mandatory Performance Requirements. This is explained in more detail below.
Because Australia is a large geographically diverse country, the BCA also provides a guidance for regional (state or territory) Performance Requirements taking into consideration such things as climate, environment, geology, etc.
Suitability of Materials
In addition to establishing the provisions for construction, the BCA also sets out the requirements for the suitability of materials used;3
A2.1 Suitability of materials
Every part of a building must be constructed in an appropriate manner to achieve the requirements of the BCA, using materials that are fit for the purpose for which they are intended.
There are a number of detailed methods included in the BCA to satisfy the evidence requirements for materials to ensure that they are fit for the purpose for which they are intended.
The BCA also directly references almost 80 material, equipment, design, installation and performance standards throughout the document.
The following definitions have been extracted directly from the BCA, and wherever any of these terms are referenced in this article they will appear in italics.
Objective, Functional Statement and Performance Requirements
Typically the opening statement for each Section (B - H and J) of the BCA comprises an Objective, Functional Statement(s) and Performance Requirements. These three requirements establish the framework and guidance necessary to identify possible Building Solutions to achieve Compliance.
It is only the Performance Requirements which are mandatory in the BCA. The Objectives and Functional Statements simply provide guidance.
Application of the Building Code of Australia and achieving compliance
The BCA provides three options for designers and constructors of buildings to satisfy the Performance Requirements for a Building Solution, these three options are;
- Deemed-to-Satisfy Provisions
A Building Solution which complies with the Deemed-to-Satisfy Provisions is deemed to comply with the Performance Requirements.
- Alternative Solution
formulating an Alternative Solution which— (i) complies with the Performance Requirements; or (ii) is shown to be at least equivalent to the Deemed-to-Satisfy Provisions;
- or a combination of the Deemed-to-Satisfy Provisions and an Alternative Solution. Some projects include aspects of the design that comply with the Deemed-to-Satisfy provisions and other individual components that have been assessed as Alternative Solutions to meet the Performance Requirements of the Code.
In simple terms, a building or structure will comply with the Performance Requirements of the BCA by adopting either the Deemed-to-Satisfy Provisions or an Alternative Solution or a combination of the two.
Prior to 1996 State or Territory building regulatory legislation in Australia established specific criteria for the construction of a building or structure. These were prescriptive in nature and could only be varied by the regulator or through specific provisions under the State or territory building regulatory legislation. Such specific provisions remain in the BCA in the form of the Deemed-to-Satisfy Provisions (sometimes known as the DtS Provisions) found in each section. The DtS Provisions establish the criteria that when followed are deemed to have satisfied the relevant Performance Requirements for the Objective.
These are traditional prescribed requirements that have been “deemed” to satisfy the Performance Requirements and can be considered as a pre-determined “recipe” for achieving compliance. Their shortcoming though is that they are not flexible and don’t always allow for different building scopes regarding design or use.
Conversely an Alternative Solution provides a another method to comply with the Performance Requirements via the development of bespoke site-specific designs that are assessed to meet the Performance Requirements from first principles or are shown to be at least equivalent with the Deemed-to-Satisfy Provisions. Alternative Solutions provided building professionals provide flexibility in construction by considering much more than the Deemed-to-Satisfy Provisions such as alternative materials, methods of construction, building size, building use and expected hazards, etc.
The following Assessment Methods, or any combination of them, can be used to determine that a Building Solution complies with the Performance Requirements:
- Evidence to support that the use of a material, form of construction or design meets a Performance Requirement or a Deemed-to-Satisfy Provision as described in A2.2.
- Verification Methods such as—
- the Verification Methods in the BCA; or
- such other Verification Methods as the appropriate authority accepts for determining compliance with the Performance Requirements.
- Comparison with the Deemed-to-Satisfy Provisions.
- Expert Judgement.4
State or territory building regulatory legislation may also provide additional assessment methods for determining compliance.
Controversy surrounding Alternative Solutions
An article about the Building Code of Australia would not be complete without a reference to the constant murmur in the community about the misuse (perceived or real) of Alternative Solutions typically to reduce construction costs and potentially placing building occupants at risk.
Formulating an Alternative Solution may require the treatment of multiple Performance Requirements (in accordance with A0.10) and often requires specialised skills to design and also to assess designs and determine compliance has been achieved. Alternative Solutions associated with fire safety provisions of the BCA should be designed by a recognised fire safety engineer and approved by a suitably qualified independent party to determine compliance.
Alternative Solutions that relate to fire safety provisions of the BCA should be developed in accordance with the International Fire Engineering Guidelines 2005 (IFEG) to reduce potential safety problems. This document was developed through a collaborative venture between the ABCB, National Research Council of Canada (NRC), International Code Council (ICC) United States of America and Department of Building and Housing New Zealand (DBH).
The fire engineering process outlined in the IFEG is described in the chart below and is expected to include a range of relevant stakeholders in the design and approval process including, fire safety engineers, architects, fire brigades, building owners and end users, regulation consultants, insurers and the authority having jurisdiction for approval. This process is aimed at ensuring alternative solutions meet the objectives of the BCA and the needs of other parties associated with the building.
In addition there is also a view that the introduction of Alternative Solutions places an additional burden on approval authorities such as Building Surveyors and Fire Authorities who may not be equipped to deal with the complex requirements of an Alternative Solution.
Legislators and building professionals should consider community concerns regarding the application of the performance based building code and ensure that Alternative Solutions are comprehensive and rigorous in their treatment of identified risks necessary to meet the objectives of the Building Code.
The review process for Alternative Solutions is supported by an extensive framework of legislation, codes, policies, guidelines, strategies, established methodologies, consultation and peer review to support building professionals.
The foundations for the current Building Code of Australia began almost 50 years ago. The BCA is a flexible framework for the construction (or alteration) for buildings and provides an ongoing reflection of community standards for health, safety and amenity of people in buildings.
Up to 65% of the BCA is related directly or indirectly to fire safety providing guidance on matters such as fire resistance, compartmentation, access and egress, fire fighting equipment, smoke hazard management, emergency lighting, exit signs, warning systems, artificial lighting and construction in bushfire prone areas.
The Fire Protection Association Australia supports members and the community by being engaged in the ongoing application and development of the BCA through legislative reform, building code development, Standards development, education and advocacy.
- Alternative Solution
- means a Building Solution which complies with the Performance Requirements other than by reason of satisfying the Deemed-to-Satisfy Provisions.
- Building Solution
- Building Solution means a solution which complies with the Performance Requirements and is— (a) an Alternative Solution; or (b) a solution which complies with the Deemed-to-Satisfy Provisions; or (c) a combination of (a) and (b).
- Deemed-to-Satisfy Provisions (DtS) means provisions which are deemed to satisfy the Performance Requirements.
- Expert Judgement
- Expert Judgement means the judgement of an expert who has the qualifications and experience to determine whether a Building Solution complies with the Performance Requirements.
- Functional Statement
- Functional Statement means a statement which describes how a building achieves the Objective.
- Objective means a statement contained in the BCA which is considered to reflect community expectations.
- Performance Requirement
- Performance Requirement means a requirement which states the level of performance which a Building Solution must meet.
- Verification Method
- Verification Method means a test, inspection, calculation or other method that determines whether a Building Solution complies with the relevant Performance Requirements.